EnvirofACS

In August 1999 at the American Chemical Society (ACS) 218^th National Meeting in New Orleans, LA the Division of Environmental Chemistry held a major symposium on Analytical Challenges for Assessing Environmental Exposures to Children. The symposium was organized by Dr. Larry Needham, Chief of the Analytical Toxicology Branch at the National Center for Environmental Health of the Centers for Disease Control and Prevention, and it was cosponsored by the ACS Committee on Environmental Improvement. The information below was abstracted from the Division's Preprints of Extended Abstracts and notes taken by Dr. Lawrence H. Keith. Copies of the Division's preprints for this meeting may be purchased from Ms. Ruth A. Hathaway at 1810 Georgia St, Cape Girardeau, MO 63701-3816 (Phone: 573-334-3827; Email: scifair@semovm.semo.edu.

The technical abstracts are grouped into the following areas:

Hence, the protection of public health must ultimately focus on developing the scientific basis for rationalizing health concerns and generating data to reduce uncertainty in making these important policy decisions. Perhaps one of the most complex and oftentimes troublesome part of characterizing potential health risks is the uncertainty contained within exposure assessments. For example, agencies currently utilize conservative assessment methodologies that intentionally exaggerate potential exposures to children. Limited biological monitoring studies designed to collect realistic pesticide exposure data for children suggest that actual exposures are generally 100 to 1000 times below those estimated by the US EPA using interim guidance methodologies and are surprisingly consistent with aggregate exposures experienced by adults. In addition, refined data developed through extensive population-based biological monitoring initiatives (i.e, the NHEXAS and NHANES federal programs) provide a robust source of data for the validation of regulatory models and for use in subsequent epidemiological and public health risk assessments. As evidenced by the amount of research being presented during this ACS symposium, considerable scientific research is underway which will help further refine the accuracy of exposure assessments used for regulatory decisions, as well as facilitate our understanding of actual health risks to children.

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Children are not 'little adults" so studies involving their exposure to environmental chemicals must be planned differently than conventional exposure studies for adults. As an example of their differences, children inhale 23 times more air, drink 3 times as much water, and eat 2 to 3 times as much food per pound of body weight than adults do. Because of their small size they also have 3 times as much surface area per pound than adults. All of these differences translate into greater exposure rates to environmental chemicals per pound of body weight than adults have.

There are also other significant differences that children have which affect how toxic chemicals may affect them. For example, they have a dynamic growth rate, their organs are still developing, and they have different behavioral patterns than adults. For example, they crawl around on the floor where toxic chemicals adsorbed to dust and other particulate materials tends to reside. This results in the potential for increased exposure from breathing and skin exposure.

Thus, in addition to the old saying that "the dose makes the poison" we can add that "timing also makes the poison" when we consider the age of the exposed person. No where is timing more important with respect to exposure to harmful chemicals than with a developing fetus. A fetus has even greater susceptibility to chemical exposure than little children because it is rapidly changing during short time periods while in the womb.

An April 21, 1997 Executive Order established an interagency Task Force on Children's Environmental Health and Safety Risks because earlier reports had identified several types of sickness that appear to be related to exposure of children to hazardous chemicals. For example, lead has been shown to cause developmental disorders linked to intelligence, mental development, and perhaps autism. In addition, asthma rates have tripled in recent years and there are increased incidences of cancer and unintentional injuries among children. The 1996 Food Quality Protection Act has special provisions for infants and children.

Progress is being made. For example, blood levels of lead in children 1 year and older have decreased from an average of 13 ug/dL in the 1970s to about 3 ug/dL now. This has resulted from removal of lead in gasoline, paint, and other products that consumers can frequently come into contact with. It has been shown that reducing blood levels of lead by 10 ug/dL results in the raising of an average IQ by 2.6 points. The implications are enormous because each IQ point has been estimated to result in $8,350 of increased earnings - this translates to $94 billion dollars in increased productivity for each year's newborns. However, consider that where the increased risk for lead exposure to young children still exists is in the homes of the poor and disadvantaged parents.

Thus, it is important to provide chemical data to the clinical profession and the population in general so that decisions can be made that improve children's health and increase probabilities of their future prosperity and productiveness in society.

Children’s micro-activity data collected during dietary events, together with the laboratory results from the transfer studies, were examined with respect to the dietary ingestion model simulation results. These limited data indicate that under conditions of high surface loading of pesticide residue, dietary contribution to aggregate exposure is potentially an important pathway of exposure for young children between the ages of 1 to 3 years old.

Young children have very different micro activities from adults and this, in turn, affects the potential routes of exposure of chemicals through dietary routes. For example, young children usually perform hand to mouth feeding almost exclusively while adults, and even older children, tend to use utensils more frequently. Thus, residues of pesticides or other chemicals picked up from surfaces such as floors, tables, and unwashed hands are more likely to be ingested by young children than by adults under the same circumstances of environmental contamination.

In addition to surface to mouth exposure the food items themselves may absorb chemical contaminants both before and after food preparation. For example, food items could come into contact with environmental chemicals present on a table, the floor, a hand, and even from pets.

The dietary contribution to an aggregate exposure assessment is potentially an important pathway of exposure, especially for young children. Environmental contamination appearing in the child’s diet can result from contamination in the food as purchased or due to preparing, serving, handling, and/or eating food in the home. If only the contamination of chemicals present in food is considered we may be underestimating the amount of exposure to young children by as much as 5 times what it is because of their eating habits. Thus, although there are many databases with information on chemical contaminants in various foods these are likely to provide an underestimated exposure if the other dietary routes are not considered.

Food contamination while eating is of special concern for children 1-3 years old, since this age group has a high frequency of hand to food, hand to surface, and surface to food interactions. These sources of food contamination may be very important in homes with high surface concentrations of chemical residue which may have resulted from outdoor air, track-in of particles, and/or indoor sources.

A computer simulation of dietary exposures indicated that pesticide transfer to food could increase the dietary intake significantly. If the frequency of hand to surface to food contacts were high, then the relative importance of hand to food would be higher than surface to food transfer. Children’s handling of the food could contribute 20% to 80% of the total dietary intake of the pesticides. Dietary exposure due to residues in the food before handling, and as usually reported in Food Basket Surveys conducted by FDA, is usually less than 20%.

Transfer efficiencies using a standard contact time of 10 minutes showed a wide range of transfer efficiencies that depended on the type of surface involved and also the chemical. Factors affecting chemical transfer included the type of food, the amount of surface contamination on it, the moisture in the food, surface area of the food, etc.

Results of range finding experiments indicate that a higher pesticide transfer occurred from the surface to food for hardwood (10 to 50%) and plastic surfaces (55 to 95%), with lower transfer efficiencies from carpet (less than 10%) and cloth (less than 5%). In general, soft surfaces characteristic of surfaces like carpets had a lower transfer efficiency of chemical to food (around 10% to 40%).

A sheet of plastic like that used in a child's high chair and sprayed with accurately measured amounts of pesticide was used to measure the variability caused by different of chemicals. Transfer efficiencies of diazinon and malathion were about 55% to 60% while chlorpyrifos was much higher at about 95%.

It is difficult to quantify exposures with children even when it is carefully documented. This is because they are very active, unpredictable, and inconsistent compared to adults. For example, children will wash their hands differently from each other. Some may only wet their hands, others may rub them together under water with or without soap, some dry their hands and others don't. After washing their hands it may take several minutes to begin eating, during which time multiple new exposure possibilities may happen. For example, after one child wiped on a paper towel another one ate it. Smearing and spilling of foods on one another and on tables or the floor is also common.

Video taping and analysis of children’s behaviors while eating were undertaken to provide information about the range and magnitude of child activity factors as they affect potential dietary contamination. The time range of eating events varied from 2 to 55 minutes, with an average of about 20 minutes per eating event. The average time food was in contact with the child’s hand was a little over 2 minutes for each eating event. Food placed on a surface other than a plate on averaged just under 2 minutes. The average number of contact times between food and hands averaged 19 times, but varied by a factor of 4 over the six children in the study.

The amount of time that a specific food item contacted the child’s hands during an eating event depended on the type of food eaten, and age of the child. Older children may use an eating utensil while very young children may not. For example, a 2 year old male handled a bologna slice for a total of about 100 seconds, and a banana for about 500 seconds, a factor of 5.

Diazinon, chlorpyrifos, malathion, cis and trans permethrin were formulated in an aqueous solution. Reference standards of heptachlor and isofenphos in an organic solvent were added to the solution. Target concentrations of 25-50 ng/cm² were applied uniformly to 400 cm² hardwood flooring, linoleum and ceramic tile surfaces in a multi hazard glove box using a 10µL multi-tipped pipette and allowed to fully dry for 2 ½ hours. Duplicate surfaces were swabbed with isopropanol wipes to determine actual pesticide levels available at the time of transfer. In addition, a modified Edwards-Lioy dermal press sampler which provides an approximation of transfer efficiencies to the skin was contacted with each surface.

Maurice R. Berry 1 , Cynthia Adcox 2 , Lisa J. Melnyk 1 , Gerald G. Akland 3 , C. Andrew Clayton 3 , Ye A. Hu 3 , Elvessa D. Aragon 3 , James M. Roberds 3 , Edo D. Pellizzari , "MEASURING DIETARY EXPOSURE OF YOUNG CHILDREN," Pages 144-145 in Preprints of Extended Abstracts, Vol. 39 No. 2, Symposia Papers Presented Before the Division of Environmental Chemistry American Chemical Society New Orleans, LA August 22-26, 1999

Range-finding studies were conducted in the laboratory to determine transfer efficiencies of various pesticide and surface combinations. A pesticide solution consisting of chlorpyrifos, diazinon, and malathion at a nominal loading range of 5-80 ng/cm² was applied and allowed to dry on hardwood floor, carpet, ceramic tile, plastic, and cloth surfaces. Food items, consisting of luncheon meats (bologna and ham), apple, bread, cheese, tortilla, and chicken nuggets, were brought into contact with the surfaces for 10 minutes. Results of these experiments indicate that a higher pesticide transfer occurred from the surface to food for hard, smooth surfaces, such as hardwood and plastic, with low transfer from carpet and cloth. For example, 80% of chlorpyrifos was transferred from a plastic surface to the apple, 69% to cheese, 40% to ham, and 38% to bread. In contrast, for these same food items and when pesticides were applied to the carpet surface, 11% transfer to the apple was the only measurable transfer.

Children are one of the more important groups from which to acquire data. Their behavior patterns such as crawling, thumb sucking and consumption of items deemed "dirty" or "bad tasting" make them vulnerable to exposure that would be unimaginable for an adult. In addition, children may be more susceptible to adverse health affects because their metabolism and respiration rate are greater than adults. For example, the average inhalation rate of a child is 17 cubic meters per day. They touch their hands to their mouths about 10 times and hour and they may touch different smooth surfaces an average of 160 times an hour.

Another consideration is that children have not had a chance to develop complete immune and endocrine systems yet. This makes them more susceptible to many sources of exposure. Thus, long-term chronic exposure to environmental chemicals is more likely to occur with children under some circumstances. Once exposed to some chemicals that are very persistent, those chemicals can reside in the body and be carried to adulthood where finally they may exert harmful effects.

Children also explore their world with their mouths. Most surfaces are available to young children in one way or another. Lower surfaces, like those on or near the floor are especially available to young children who crawl and are otherwise close to the floor. And, the floor is where most particulate materials (dust, dirt, etc.) settle. In addition, being close to the floor children breath a different population of particulates than adults and chemical pollutants tend to adsorb to particulate matter. Finally, children don't mind messes; in fact they often cause them. The implication of messes is that dermal exposures may be greater if particulate matter or other sources of environmental chemicals (dirt, mud, etc.) are involved.

Data assessing exposure for this special group is drawn from many areas, all of which must be quality assured. Pesticide exposure measurements can require the collection of urine. Lead exposure usually requires blood samples be drawn and hair is also sometimes used as an indicator of mercury exposure in the diet. In addition to samples acquired directly from the child, measurement of time and activity patterns, collection of clothes or toys and even observations of behavior, require quality assurance. Each of these types of data have their own level of reliability that can be expected and all have their own quality safeguards that can be implemented. For example, biological samples need to be collected using protocols that not only assure minimal cross contamination but also insure temporal quality as well. Collecting urine samples to estimate exposure weeks after the pesticide application is likely to produce data showing largely "non detects". Conversely collecting hair samples for mercury three days after ingestion of a large quantity of fish is also likely to produce data of no value. Collecting both from a child who has no desire to submit either sample can make the whole process tragic for all involved.

Collection of activity pattern may require observable techniques since young children can not complete questionnaires and have poor concepts of time. Observational techniques are only effective if the observers are well trained and are reproducible. For example, a child with high lead blood levels lived in a house that was clean and had low lead concentrations. It required observation of the child's behavior to learn that a favorite toy she loved to suck on contained yellow lead chromate as the dye and which was the source of her lead contamination.

To carry out an effective study with children requires the quality assurance officer to be part field technician and part parent, with equal importance to each task. The role of parent is often more important when designing or approving sample collection protocols that work. The most important thing with this type of work is to expect the unexpected and be ready to go with the flow.

Any multipathway model for children must include all three exposure routes: inhalation, dermal contact, and ingestion. In addition, ingestion should be divided into two important pathways, dietary and nondietary ingestion.

To estimate dermal exposure, microenvironments are defined by location and surface type (e.g., indoors at home on carpet). For the NERL studies, four locations with three surfaces each have been defined.

• Indoors at home: carpet, hard surface, upholstered furniture or bedding
• Outdoor at home: grass, soil, pavement
• Indoors at daycare: carpet, hard surface, upholstered furniture or bedding
• Outdoor at daycare: grass, soil, pavement

Three macroactivities have been defined: sleeping/napping, active play, and quiet play.

The resulting me/ma are intended to account for different microenvironments that could have different residue concentrations, different surfaces that effect transfer rate, different activities of the child that would effect the transfer coefficient, and different clothing patterns for the child that would effect the surface area available for transfer. The dermal exposure associated with a given me/ma (e.g., actively playing on the grass in the yard) is measured and used to develop an activity- and microenvironmentspecific transfer coefficient. Exposure can then be estimated individually for each of the microenvironments where a child spends time and each macroactivity that the child conducts within that microenvironment. Exposure over the 24-hour period is the sum of all of the me/ma exposures.

The following data are then required for each me/ma to estimate dermal exposure:

• Transferable surface residue concentrations for each of the microenvironments (location-surface combinations.
• Amount of time the child spends in each me/ma over 24-hours.
• Fraction of body not covered by clothing while in the microenvironment..
• Dermal transfer coefficient for each me/ma.

For non-dietary ingestion, exposure is estimated individually for each of the microactivites from which non-dietary ingestion occurs (both hand-to-mouth and object or surface-to-mouth contacts are included). Exposure over the 24-hour period is then the sum of all of the individual exposures.

The following information is required to assess non-dietary exposure resulting from surface to mouth activities:

• Data on important microactivities that lead to surface to mouth ingestion.
• Transferable residue concentration for the objects and surfaces mouthed by children.
• Information on fraction of residue transferred from surface to mouth during a mouthing event.
• Number of mouthing events over 24-hours.
• Suface area of objects and surfaces contacted by mouth . To assess non-dietary exposure resulting from hand-to-mouth activities, the following data will be required.
• Data on important microenvironments/macroactivities that lead to hand-to-mouth ingestion.
• Residue concentration on the hands.
• Information of fraction of residue transferred from hand to mouth during a mouthing event.
• Number of mouthing events for each me/ma over 24-hours.
• Suface area of hand contacted by mouth.

For dietary ingestion, exposure is estimated by summing contributions from pesticide residue on the food prior to handling in the residence, pesticide transferred to the food during contact with contaminated residential surfaces, and pesticide transferred from surface to hand to food during handling and eating of the food. Data requirements are similar to those for non-dietary ingestion with the addition of specific information on the concentrations of pesticide residues on foods coming into the house and on how children handle food.

The Food Quality Protection Act of 1996 (FQPA) requires EPA to upgrade the risk assessment procedures for setting pesticide residue tolerances in foods and has identified several factors that must be considered in the revised process. Specifically, FQPA requires that the tolerance setting process must consider:

• the special susceptibility of infants and children as well as other subpopulations;
• cumulative effects of exposures to the pesticides having a common mode of action; and,
• aggregate (multipathway) exposures including those from food, water, dust, soil and air.

A three-phased approach is being used to develop and coordinate specific project tasks in support of FQPA research needs. This strategy uses careful planning and scientific review to develop a coordinated research program.

• Phase 1 includes the development of a simple conceptual model for nonoccupational exposure to pesticides. It includes all of the potential sources, pathways, activities and other factors that may effect exposure to pesticides. A series of research questions is developed from the model. The questions provide a framework for systematically reviewing the literature and evaluating the important factors for measuring and assessing children’s exposures to pesticides.
• Phase 2 involves information gathering to assess the current state of the knowledge with regard to pesticide sources, relevant pathways, microenvironmental concentrations, human activity patterns, monitoring methods, and relevant models. This information should allow us to identify those pesticides, microenvironments, and activities that represent both the highest risk and the greatest uncertainty. It will also allow us to identify methods that are needed for the conduct of human exposure studies. Specific research studies are designed to fill the most important data gaps.
• Phase 3 is for the implementation of the specifically designed research studies. This includes conducting exposure studies, documenting developed methods, transferring data outputs into databases, and conducting statistical analysis and modeling of the data.

In conducting studies with children it must be emphasized that they are not just little adults. They have higher exposure rates to environmental chemicals, their activities are very much different from adults, the pathways with highest exposures are often uncertain, they have large variances in their activities, and they are difficult to study.

Five different age groups have been determined for children's exposure assessments:

0 - 6 months (infants)

6 - 12 months (crawlers)

12 - 24 months (young toddlers)

24 - 36 months (older toddlers)

3 - 5 years (preschoolers)

Within these different age groups microenvironments and macroactivities are very different. Routes of exposure include surface-to-skin, skin-to-mouth, and surface-to-mouth. These are affected by age, activity level, and macrolocation (i.e., in the home, in a day care facility, or outside).

Historical reconstruction of exposure to compounds of toxicological and epidemiological interest was first done in radiation biology and radiation epidemiology. For example, women exposed to radiation before they were 20 years old had higher susceptability to cancer. Methodological problems and solutions from these fields thus provide important clues to the problem of dose reconstruction for childhood exposure to persistent bioaccumulative chemical carcinogens, genotoxic and immunotoxic agents.

Children have special characteristics that adults lack. For example, their growth is very active and their nervous system is under development. Their neruological and vascular tissues have special growth requirements and they are sensitive to accute poisoning. In addition, their metabolism, energy, energy expenditure, and energy intake per unit mass varies greatly with their age.

As part of the environmental exposure characterization work and in support of the upcoming geographical information analyses for Congressionally mandated Long Island Breast Cancer Study Project (LIBCSP), 220 regulated chemical compounds of concern as potential endocrine disruptors were evaluated and ranked on several chemical, environmental, toxicological and epiderniological characteristics. About one half of the LIBCSP listed compounds are currently being measured in various media, such as blood, urine, drinking water, yard soil, and house dust in a population-based case-control study of the role of environmental exposures in excess breast cancer in Nassau and Suffolk Counties, NY.

Breast-feeding is the major source of persistent organochlorine chemicals among U.S. infants. It leads to higher levels of organochlorine chemicals among breastfed children as old as 8 years. Given the higher levels of this type of chemical pollutant among blacks and Hispanic women, their children will also have higher levels, compared with Caucasians. PCBs and dioxins may be contaminants in some sources of chemical pollutants and they also may pose serious threats to children because they can act as endocrine disruptors. Increasing body mass dilutes levels of organochlorine chemicals among growing children, such that PCB concentrations in body lipids decline about 50% faster than in adults. Children absorb proportional amounts of organochlorine chemicals from a contaminated environment, and consequently have levels quite similar, to their parents.

Dermal absorption is also potentially a continuing major route of organochlorine chemical exposure among small children, as documented by a number of recent studies showing high levels in many US homes of DDT and other organochlorine chemicals in indoor dust.

Absorption and excretion in children are governed by body mass, metabolic capacity, and surface area. Although these attributes differ markedly in children compared with adults, there is little information available on actual exposures about quantitative differences. However, many persistent organochlorine chemicals have similar half lives of around 7 to 10 years. Half lives of DDT, PCBs, dieldrin, and similar chemicals are also about 7 years. Organochlorine chemicals as a class have shown a steady decline from 1965 through 1993.

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Dried-blood spots (DBSs) as a sample matrix offer many advantages over liquid samples and simulate the stability of lyophilized samples. DBSs are easy to transport from diverse locations; most analytes are very stable in DBSs; they represent a whole blood sample; they require minimal storage space; and they pose low biological hazards.

Historically, the primary disadvantage has been sample volume and reconstitution to a neat sample. These disadvantages are diminishing with advances in technologies. DBSs are easily collected by finger or heel sticks. DBSs from newborns have been collected since 1960. Today, DBSs are routinely collected from all newborns in the US each year to screen for inborn errors of metabolism as well as collections occur worldwide. In several states, the leftover samples from this testing are stored with linked information indefinitely.

The value of these stored samples for DNA and other analytes is speculatively immense. Several million samples exist in these repositories. The existence of these population-based samples that represent maternal-fetus exposures and the advantages of DBSs should drive pilot studies to pursue methods for measuring toxicants in DBSs. We have examined the potential of this matrix source in a small preliminary study.

There are millions of DBSs on file in various states. They represent the largest genetic testing initiative in the nation. Over 4 million DBSs are collected each year from heel sticks of babies before they are discharged from a hospital. These samples may be analyzed for 2 to 10 genetic and non-genetic disorders of children after they leave the hospital. However, other than for lead and selenium concentrations in the blood, DBSs have not often been analyzed for environmental pollutants.

In a recent study DBSs from 10 newborns were tested for DDE, a metabolite of DDT, and all 10 tested positive for this chemical. Results ranged from 0.37 - 1.87 ppb with a mean of 0.84 ppb. Although sample volumes and concentrations were very small, the data illustrated the possibilities for the test and sample source.

The DREAMS Project (Developmental Research on Early Attention and Memory Skills) is a 5 year, prospective study of the effects of lead poisoning on the development of attention, memory and behavior regulation skills. The subjects are children of African American, Native American, Caucasian, Latino, and Hmong descent, recruited before 8 months old. The children are at high risk for lead poisoning because of the housing conditions, proximity of highways and industry, and economic disadvantage experienced by their neighborhood.

Experience with this Project was used to highlight the challenges inherent in community-based research within diverse and economically disadvantaged neighborhoods. The challenges and responses to them focus on the hurdles faced when working within a community collaborative and by the characteristics of the community residents serving as subjects and staff. The investigation of community environmental health problems can lead to important findings that can inform the scientific community and create real community change. Addressing these research questions through a community-based research approach is of great benefit to the community and can result in improved methodology, quality of data collected, as well as effectiveness of dissemination of information discovered. However, it is paramount that the potential obstacles be anticipated and planned for, or detected and promptly responded to, in a manner that preserves scientific rigor yet respects the community.

Children are the most susceptible population to lead exposure because 1) they have more opportunity for contact with lead sources due to their activities, 2) lead absorption occurs more readily in a child as compared to an adult, and 3) the child’s development is more vulnerable to lead than adults. Low levels of lead in the blood have been shown to cause adverse health effects: the level of concern for children is currently 10 ug/dL.

The contribution of dietary exposure of lead to increased blood lead levels is not well characterized and is becoming a larger portion of exposure as others are decreasing (e.g., from leaded gasoline, lead in paint, lead solder in food cans, etc.).

Dietary exposure was evaluated by collecting food samples that were representative of the foods the young children who participated in the study ate in their homes. A 24-hr. duplicate of all foods plus sentinel foods, i.e., individual food items used to represent foods for exposure during handling, were collected from 48 children. Seven of the participants were revisited three times and three participants were revisited once to obtain information on the variation in dietary intakes. Drinking water was evaluated both as part of the beverage sample and by itself. Additional information collected included lead concentrations from hand wipes, floor wipes, and venous blood; and questionnaire responses on activities related to exposure. A general conclusion is that, for the children in this study, food eaten and handled in a lead contaminated environment increased dietary exposure to lead.

Lead exposure in children may come from multiple sources including lead paint, lead pipes, solder, crystal, leaded gasoline (which is still used in some countries), and lead-glazed pottery. Although lead exposure has decreased in some population segments, it has not in others. For example, data from phase one of the Third National Health and Nutrition Examination Survey (NHANES III) demonstrated that 37% of African-American children in large urban areas had lead levels above the CDC-recommended level of concern of 10 ug/dL.

It is well known that the presence of lead in a child's blood may have detrimental effects on the child's IQ level. As knowledge has increased about the harmful effects of lead exposure, especially in young children, guidelines for physicians regarding the concentration of lead in blood which is harmful have progressively been modified to reflect lower blood lead levels. The publication "Preventing Lead Poisoning in Young Children: A Statement by the Centers for Disease Control -October 1991" recommended the measurement of blood lead as the screening procedure of choice.

As a result of CDC's efforts to develop improved technology, The world's first hand-held blood lead analyzer, called LeadCareÒ , was developed, manufactured and marketed under a partnership between ESA, Inc. of Chelmsford, MA and AndCare, Inc., Durham, NC. This device was approved by FDA on September 10, 1997, was demonstrated to HHS Secretary Donna Shalala by CDC staff on September 15, 1997, and was used to test the blood lead levels of Secretary Shalala and Vice President Gore (among others) during the September 21-23, 1997 meeting of the Gore-Chernomyrdin Commission in Moscow. Now it is possible to test a child's blood in field settings, physicians' offices, or public health clinics, and have results available in a few minutes so that confirmatory testing and intervention can begin immediately. This new technology also permits blood lead screening in less developed countries where central laboratory lead testing is impractical.

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Current literature indicates that in utero exposure to certain environmental pollutants (e.g., DDT and PCBs) may result in toxicological consequences which would not be observed in exposed adults. Lowered birth weight, depressed cognitive function, and delayed maturation of motor abilities represent potential outcomes of prenatal exposure to environmental pollutants. These data raise sufficient concerns to warrant further investigation. Studies are currently being conducted in the Faroe Islands in conjunction with over 1,000 women who had high exposure to mercury, selenium, and lead from consumption of a high fish diet to determine the impact of in utero exposure to environmental pollutants. The Faroe population is unique: 1) because of their reliance on fish (mostly cod), whale (pilot) blubber and muscle to constitute a large percentage of their diet; and 2) because Faroese women have a very low participation rate in alcohol consumption and smoking. In addition, they represent a very homogeneous population.

Maternal hair, umbilical cord blood, and umbilical cords were collected from 1022 consecutive births that occurred in the Faroe Islands in 1986-1987. Trace metals were determined in maternal hair and umbilical cord blood. A select group of organic compounds have been determined in the umbilical cords. Umbilical cord analysis, quantitation of organic analytes, correlation among the analytes on a whole weight and lipid adjusted basis form the focus of this paper.

Umbilical cords were obtained from birthing mothers in the Faroe Islands from 1986-1987. Cord samples (1-3 g plus three surrogates) were homogenized and extracted using hexane:acetone (1:1) three separate times, the extracts were combined, and washed with a 2% solution of sodium sulfate. The organic phase was dried through a sodium sulfate column and the eluate split (dependent on the sample weight) so that the predominant amount of sample was eluted through a micro silica gel column and used for gas chromatographic analysis and the remainder was used for gravimetric lipid determination.

The analytes detected were found to be significantly correlated with each other on a whole weight basis and there was an observed improvement in the correlation on a lipid adjusted basis. Percent lipids determined gravimetrically had a median value of 0.18 percent. DDE and PCBs were found in every sample that was analyzed. This is not surprising since fish and whale blubber, food high in fats and lipids which tend to bioconcentrate these kinds of pollutants, were high consumption foods in the women's diets.

However, with the exception of DDE none of the analytes had median values above 0.50 ppb. This is approaching the detection limit for this analytical technique. The low lipid content of the umbilical cord is a contributing factor. Yet, with the projected increase in the use of umbilical cord blood as a source of stem cells the umbilical cord may evolve as a matrix alternative for assessing in utero exposure to compounds of environmental concern.

Environmental exposure to some toxic chemicals can have serious effects to the immune system of children that continue on to adulthood. For example, the immune systems of children can be affected so that they are more susceptible to infections and other disease states.

Cytokines are peptides that regulate proliferation and growth of cells in the body. They serve as the molecular communication system of our immune systems. A recycling chromatographic system for assessing immune system damage or impairment in infants exposed to pesticides was developed that measures the expression of different chtokines, thus providing an overview of the degree of immune impairment in an individual.

In the early 1970s 25 children were identified who had been exposed to chlordane and heptachlor. Of these, 15 showed chemical signs of allergy and 10 showed no signs of allergy. Also, at the same time a control group of 25 children were identified. The health of these 50 people has been tracked for twenty five years and some associations of physical sickness can be made with those exposed to the pesticides.

Chlordane and heptachlor have been associated with medical problems that include clinical allergy, respiratory infections, skin infecations, early onset of autoimmunity, and increased incidences of cancer.

The 15 children initially identified as "sick" from exposure to the pesticides in the 1970s continue to remain sick. They had greatly elevated inflammation markers one month after exposure to the pesticides. They also had elevated neurogenic inflammation markers. Now in adulthood, they have more upper respiratory problems than the other 10 children and control children; however, none show signs of asthma. These 15 "sick" children also have different immunosurpression profiles from the others and, as adults, they are subject to more infections, decreased immunity, and, as mentioned above, increased respiratory problems. In addition, they showed increased dermal lesions, reduced interferon production and increased viral infections.

Thus, the effects of exposure at an early age to chlordane and heptachlor has continued to cause health effects into adulthood.

Experiments were conducted to determine the dislodgeable residues of organophosphorus flea control insecticides from the fur of dogs. There are 34.6 million households in the United States and 37% of these (12.8 million) have dogs. In addition, it is estimated that about 20% of the households with dogs (2.5 million) have young children who, of course, come in contact frequently with their pets. The concern for children is the potential cumulative effects and body burden of the insecticides used in flea control products. The chronic exposure effects of the types of chemicals, which are neurotoxins, to young children over time is unknown.

Flea control with most dogs is maintained by using flea collars or by dog dips, both using chemical insecticides as their active ingredients. The mechanism of flea control is entirely different between the dog dips and the flea collars. Dog dips are designed to leave a residue of insecticide on the dogs fur and skin. Flea collars have the insecticides imbedded in them and the chemicals slowly migrate out of the collars to the fur around the dogs neck. No adverse effects were observed with any off the dogs using the dips and collars as per the instructions with them.

Since there were no validated or even generally accepted procedures for determining insecticide residues which could be transferred from the fur of dogs to another surface suitable for chemical analysis, a new procedure was developed. It consists of rubbing the fur of the dogs at set intervals after application of the insecticidal product (either a flea dip or a flea collar) with white cotton gloves over a 10 inch area of the central portion of the back of the dog for an exact 5 minute period.

The gloves are previously washed with detergent and then pre-extracted with solvent, and are not reused. After use on a dog the gloves are subjected to routine procedures of solvent extraction and gas chromatographic analysis of the extracts. In addition, since the insecticides of study were anticholinesterase organophosphates, blood samples were taken to obtain serum for cholinesterase assay by standard spectrophotometric techniques to serve as a biomonitor of insecticide internalization by the dog.

The initial three studies involved a chlorpyrifos dip, a phosmet dip and a tetrachlorvinphos collar. Only the fur and the blood of dogs were sampled. The last study, which is currently on-going, is a study of chlorpyrifos residues from a flea collar on a pet dog along with monitoring of the dog for serum cholinesterase inhibition, and additionally the biomonitoring of the chlorpyrifos metabolite 3,5,6-trichloropyridinol in the urine of an adult and a child (age range of 4-12 years) in the households at early time points in the study.

Residues of the insecticides used in the two dip formulations are high initially, but they dissipate quickly, and are extremely low by the time of the next approved dipping. Therefore, there was no evidence of an accumulation of insecticide with subsequent dipping. Transferable residues of about 1 mg of chlorpyrifos on a glove on the day of treatment decreased to 25% of that level within 4 days and to 10% of the initial level within 3 weeks. Phosmet transferable residues of about 3 mg on the day of treatment decreased by 2.6 times by day 1 and continued to become progressively lower over time.

In contrast, the dissipation of residues from the tetrachlorvinphos collar was slow (consistent with its recommended 4 month useful life span), and initial dislodgeable residues from the collar itself were very high. As would be expected, the highest levels of insecticide were found near the flea collar with concentrations decreasing towards the dog's tail. Transferable residues from the chlorpyrifos collar reached their peak concentrations of 0.5 mg after 2 weeks.

A longitudinal biological monitoring study is being conducted in the central Washington state area. This is an agricultural community with fruit tree orchards (primarily apple, pear, and cherry trees) as the major industry. The primary objective of this study is to determine whether there are significant temporal changes in children's exposure to organophosphate pesticides, in conjunction with the use of organophosphate pesticides in the nearby orchards.

This study was based on the hypothesis that children living in the agricultural community are being exposed to organophosphate pesticides from the spray drift or from their parents who work in the orchards. Their parents may bring home some of the pesticides for personal use at home. In addition, the children may be exposed to them through their diet as well as from environmental close proximity to where the pesticides are used. Often the homes of agricultural workers are across the street, adjacent to, or partially surrounded by the orchards which are sprayed. The pesticides frequently used in this area include azinophos-methyl (Guthionä ), Phosmet (Imidanä ) and chlorpyrifos (Lorsbanä for agricultural products and Dursbanä for household products).

Biweekly spot urine samples have been collected from a cohort of 49 children from 44 different families since January 1998. Urine samples were analyzed for 6 clialkyjpbosphate for organophosphate pesticide metabolites using a GC-FPD method.

For comparison, a cross-sectional study with repeated sampling was conducted to evaluate organophosphate pesticide exposure through biological monitoring of children ages 2-5 years old, residing in non-agricultural communities in the Seattle metropolitan area. This survey of children's exposure to organophosphate pesticides in urban/suburban settings will provide useful information regarding exposure variability in these environments, and will help to determine if further investigation is warranted. One hundred children from 94 different families were included in this study.

A pilot study was also conducted to examine the relative contribution of various exposure pathways to organophosphate pesticides for children living in agricultural and non-agricultural environments. Thirteen families (6 from agricultural and 7 from non-agricultural communities) were recruited for this study. Children's one-day exposure to organophosphate pesticides was assessed by collecting environmental samples including duplicate meals for the day, drinking water, hand-wipes, household dust, outdoor soil, and a 24-hour indoor air sample. Four spot urine samples throughout the 24-hour sampling period were collected from each child following the collection of the food samples.

An important finding was that levels of organophosphate pesticides were much higher in house dust than in soil samples. This is because this class of pesticides decompose in soil when exposed to moisture. House dust, on the other hand, remains dry and maintains the pesticides in their original form much longer. In addition, the concentration of organophosphate pesticides in the house dust could be correlated with distance of the house from the orchards. As the distance increased from about 200 feet to a quarter of a mile the concentration of organophosphate pesticides in the house dust decreased. In general the house dust collected from indoor carpeted areas of agricultural workers had concentrations of organophosphate pesticides 7 times higher than the house dust collected in similar areas from urban sites. This is of concern since young children crawl around on these areas and also breathe air with stirred up dust on the floors. The study found that children of agricultural workers have about a 4 times greater exposure to organophosphate pesticides than other children in the same community.

A 1999 study revealed that children from suburban families in this same area have intermediate exposure levels to organophosphate pesticides (i.e., they are lower than children from agricultural workers but higher than children from urban areas). This is reasonable considering the potential lower, but still occasional, use of organophosphate pesticides in suburban lawns and gardens. Within the urban and suburban communities it was determined that about 89% of the organophosphate pesticide exposure came from dietary exposure while only about 11% of the exposure came from house dust. On the other hand, about 58.5% of the organophosphate pesticide exposure with agricultural worker's families came from house dust. Less exposure came from dietary sources (32%) and dermal sources (9.5%)

M.K. O’Rourke, P. Sanchez Lizardi, S.P. Rogan, A. Aguirre 1 and C.G. Saint , "YOUNG CHILDREN AND FIRST MORNING VOIDS," Pages 121-124 in Preprints of Extended Abstracts, Vol. 39 No. 2, Symposia Papers Presented Before the Division of Environmental Chemistry American Chemical Society New Orleans, LA August 22-26, 1999

Organophosphate pesticides are used widely in agriculture and most agricultural workers in the United States encounter them. Exposure can occur through all pathways. Community residents have the greatest concern of exposure through aerial spraying of pesticide and pesticide drift. In Yuma Co. Arizona, one or more urinary metabolites to organophosphate pesticides were observed in 28% of the children 6 years of age.

This should not be surprising because farm workers in highly agricultural states frequently live near the edge of the fields or in small adjacent communities with their families. Organophosphate pesticides (such as malathion, methyl parathion, oxydemeton methyl) are used in the fields of Arizona and other states against agricultural pests and in homes to combat termites and roaches (chlorpyrifos, diazinon). Frequency of pesticide poisoning among agricultural workers depends on the training, safety practices and knowledge of the worker. However, many workers are unaware of these safety practices resulting in increased risk of exposure and poisoning. Children of farm workers are at a great risk for routine secondary exposure to pesticides.

Although there have been very few studies to assess children exposure to pesticides and their potential health effects, it seems reasonable to assume that, in general, children face more risks to pesticide exposure than adults. Pound for pound of body weight, children eat more, breath more, and have a faster metabolism. Behaviorally, they tend to play on the floor or lawn where pesticides are commonly applied and have more frequent hand-to-mouth contacts. Risk of exposure is enhanced if the children live in agricultural communities.

Urinary metabolites (alkyl phosphates) have been used in other studies to evaluate pesticide exposure. The goal of this study was to determine whether children living in agricultural regions experience increased pesticide exposure. Initial results of urinary metabolite frequency using an organophosphate pesticide screen for children between the ages of 2 and 6 years who are potty-trained.

Of the 150 households enrolled, two children under the age of 6 years were recruited in six homes for a total of 156 subjects under the age of six. The study design also called for evaluation of some older sibling for comparison; 40 older children were recruited. 49% of the population was recruited from San Luis, AZ, a town on the US-Mexico border; 46 % were recruited from Somerton, AZ.s. All children were Hispanic and most households were bilingual. 51% of the children were male and 49% were female.

The alkyl phosphates were measured in the urine of 122 children 6 years or younger who were able to urinate into the specimen cup. Dimethylphosphate has the greatest recovery among the alkyl phosphates. Thus, in most studies dimethylphosphate appears most commonly. In this survey dimethylphosphate was present above the detection limit in 23% of all samples.

Ken Sexton 1 , E.D. Pellizzari 2 , J.J. Quackenboss 3 , P.J. Lioy 4 , P. Shubat 5 , J.L. Adgate 1 , R.W. Whitmore 2 , T.R. Church 1 , C. Stroebel 5 , G. Ramachandran 1 , A. Clayton 2 , A. Fredrickson 1 , M. Roberts 2 , I.A. Greaves 1 , N. Freeman, "MEASURING CHILDREN’S EXPOSURE TO HAZARDOUS ENVIRONMENTAL MIXTURES: TWO CASE STUDIES ILLUSTRATING COMPLEXITIES AND CHALLENGES" Pages 118-119 in Preprints of Extended Abstracts, Vol. 39 No. 2, Symposia Papers Presented Before the Division of Environmental Chemistry American Chemical Society New Orleans, LA August 22-26, 1999.

The Minnesota Children’s Pesticide Exposure Study (MNCPES) is used to illustrate the practical realities and operational challenges of measuring children’s exposure to complex environmental hazards. This study is designed to respond to the research needs identified by the 1993 National Research Council report, Pesticides in the Diets of Infants and Children, and the related challenges of implementing the Food Quality Protection Act.

The primary objective of the study was to characterize children’s exposure to selected organophosphate pesticides through a combination of personal exposure measurements and complementary analyses of biological samples, environmental samples, and activity patterns of children. The central focus was on measuring exposures to four pesticide compounds (chlorpyrifos, diazinon, malathion, and atrazine). These pesticides were selected because of their frequent use, presence in multiple environmental media, expected population exposures, and related toxicity. In addition, concurrent measurements were made of other chemical pollutants including polycyclic aromatic hydrocarbons, 2,4-D, and metals in house dust and volatile organic chemicals (VOCs) in outdoor, indoor, and personal air samples.

One hundred and two children and their households participated in the study. Samples included dermal contact (102 dermal press samples from floors and 52 dermal hand samples and rinses), foods (132 samples), and beverages (101 samples), and environmental concentrations of chemicals from indoor and outdoor air, surface dust (186 samples), soil (102 samples), drinking water (55 samples), and 267 urine samples (from 90 children). Preliminary data from urine samples reveal mean concentrations of 0.2 ppb atrazine, 0.7 ppb of 2,4-D, 1.1 ppb of MDA (a metabolite of malathion), 2.6 ppb of 1-naphthalene, and 9.1 ppb of TcPy (a metabolite of chlorpyrifos). Thus, chlorpyrifos was the most prevalent pesticide to which the children were apparently exposed

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Chlorine-disinfected household tap water contains trihalomethanes (THMs) due to reactions between free chlorine and organic matter in the water. Human exposure to these compounds depends on the source of the water, level of organic matter, treatment method, and personal activities such as bathing, showering, and drinking. Because of THMs in tap water public health messages sometimes warn pregnant women not to drink tap water.

A purge & trap/gas chromatography/mass spectrometric method for measuring THMs in human blood (5 mL samples) with detection limits in the parts-per-quadrillion range from 0.2 ppt to 40 ppt linearity is described. This method allows determination of background levels of THMs in people, the effect of typical daily activities on internal dose levels, and the changes in blood levels with time following exposure. It is important to understand the human levels resulting from different routes when proposing public health actions to lower exposure in vulnerable populations.

Activities investigated included showering for 10 minutes, bathing for 10 minutes, and drinking 1 liter of water in a 10 minute period. Shower and bathing water temperatures were maintained at 37 degrees Centigrade and drinking water was maintained at 15 degrees Centigrade.

Chloroform, which is produced as a chlorination disinfection byproduct was present at 20 ppb (± 1.6 ppb) in drinking water, at 30.8 ppb (± 5.9 ppb) in the warmer bathing water, and 30.3 ppb (± 5.1 ppb) in water used for showering. The corresponding levels of chloroform in blood were measured at 50 ppb from drinking water exposure, 130 ppb from bathing water exposure, and 140 ppb from showering water exposure. This, drinking water had little effect in raising chloroform levels in the blood but bathing and showering had significant effects. However, it was noted that levels of chloroform and other haloforms decreased rapidly after the exposure was completed.

The hot water used for bathing and showering had higher levels of THMS due to the more efficient reactions of chlorine with humic materials at higher temperatures.

Other factors to include in assessments are that a child's surface area is greater than an adults per unit mass. Also, exposure to chloroform and other THMs is the aggregate of inhalation plus dermal exposure while bathing is primarily reduced to only dermal exposure. One would expect the blood levels from showering to be more different than they were from bathing.

Another factor to consider is the season in which the exposures occur. Since the fall season produces higher levels of humic materials in many drinking water sources from leaves the concentration of chloroform and other THMs may be higher during this season of the year in some vicinities.

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Recent interest has developed over endocrine disrupting contaminants which have been linked to several regulatory, developmental and growth mechanism abnormalities in children. Environmental contaminants that have the potential to disrupt endocrine function include inorganic chemicals (such as lead and mercury), naturally occurring toxins (such as phytoestrogens and mycotoxins), and synthetic organic compounds (such as pesticides, dioxins, and polychlorinated biphenyls).

This work focuses on the latter class of compounds, and assesses the potential of a new analytical method, time-compressed gas chromatography/time-of-flight mass spectrometry, for faster screening and testing of endocrine disrupters in biological samples. In time-compressed gas chromatography the analysis time is dramatically decreased through the use of shorter columns, faster temperature programming and higher carrier gas flow rates.

For example, time-of-flight mass spectrometry is ideally suited for this type of operation because of its fast scanning capability. A 40 minute GC/High Resolution MS method for serum PCB analysis was reduced to 300 seconds using time-compressed GC/TOF MS while maintaining low pg/µL sensitivity levels.

Plastics additives include several classes of compounds such as phthalate esters, alkyl phenols, adipates, bisphenol-A, and terephthalates. However, phthalate esters (phthalates) are the most commonly used plasticizers in the United States. They are used to make polyvinyl chloride (PVC) plastic pliable. Global usage is reported at more than 4 million tons per year.

Children's exposure to phthalates comes in the form of plastic consumer items such as toys, rain coats, and some limited food packaging. Other uses of phthalates in plastics include blood bags, flexible plastic tubing, perfumes and cosmetics, wood finishes, and some paints.

The potential role of dialkyl phthalates in causing increased risk of cancer and reproductive dysfunction has led to the need for a rapid, sensitive and precise assay for phthalate metabolites in physiological matrices. It has been shown that the general population is exposed to significant levels of plastics over long periods of time. In addition, elevated cancer and reproductive dysfunction has been attributed to high doses of phthalates in animal tests. US EPA currently classifies diethylhexyl phthalate, the most common and ubiquitous phthalate as a rodent carcinogen. In addition, di-butyl phthalate has been shown to cause testicular atrophy in rats and mice. It has also demasculanized fetal male rats and displayed anti-endrogenic effects in rodents. Of course, these test results are of questionable relevance to humans. Current data indicates that the benefits of phthalate esters as plasticizers outweigh their potential risk to society.

A HPLC-MS/MS method for the quantitative detection of eight phthalate monoesters (major phthalate diester metabolites) in human urine has been developed. The method uses enzymatic deconjugation followed by solid phase extraction, reverse phase HPLC, and APCI-tandem mass spectrometry. This selective method allows for rapid detection (7.7 minute total run time) of 8 metabolites of commonly used dialkyl phthalates in human urine (1 ml) with limits of detection in the low ppb range.

Assay precision is improved by adding internal standards ( 13 C4-labelled) for each of the eight analytes, as well as conjugated internal standard to monitor deconjugation efficiency. Application of this selective, sensitive and rapid method will help elucidate the potential role of dialkyl phthalate plasticizers in human disease.

The average blood levels of lead in the U.S. population decreased from 16 ug/dL in 1976 to about 2.5 ug/dL in 1994.

The National Health and Nutrition Examination Surveys, directed by the National Center for Health Statistics, CDC, are the primary mechanism by which national normative values for the United States population are established. The NHANES Surveys started with NHANES I (1971-1975) and continue with NHANES 1999+ which began in April, 1999. Unlike previous surveys, NHANES 1999+ will have the option of changing its analytical menu every year, and will become a continuous survey.

Monitoring the health of children of all ages is a critical focus of the NHANES. The survey is designed to incorporate measures of overall nutritional biochemistry as well as environmental toxicants and includes the following analyses, performed by the Division of Laboratory Sciences, NCEH, CDC, on all or a subset of children of different ages: essential and heavy metals, non-persistent pesticides, organophosphate pesticides, polyaromatic hydrocarbons, phthalates, phytoestrogens, persistent organochlorine pesticides and PCBs, dioxins, furans, and coplanar PCBs.

Asthma in children has increased by more than 33% over the past 30 years. Childhood cancer has increased by more than 25% over the past 30 years. In addition there has been increased incidences of learning disabilities, attention deficiency syndrome, and other behavior related disorders (for example, autism) recently. In addition, it has been noted that these health effects occur more frequently in lower social economic groups. In response to these concerns there has been an enhanced recognition of potential health problems in children, new research programs instituted at NIEHS, Presidential Executive Orders, and new legislation in the form of the Food Quality Protection Act and the Safe Drinking Water Acts of 1996.

Hazards to young children from the more toxic pesticides registered with the Environmental Protection Agency (EPA) were evaluated. Many of the most toxic pesticides are sold as concentrates registered for use in pet products and other residential applications such as disinfectants, weed killers, and insecticides for garden and lawn care.

Data on chemical poisonings and exposure incidents were obtained from the American Association of Poison Control Centers; product-specific data came from EPA’s Reference Files Reporting System; and, end-use production data were from Section 7 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

Chemical poisoning of children under 6 years usually involved ingestion of products that were stored at floor level or eye level to the child.

Medical outcomes were evaluated by the toxicity rating of the pesticide. Only child poisonings from toxicity level I and II pesticides were included in the study. Toxicity level I chemicals have an oral LD-50 or less than 50 mg/kg while level II chemicals have an oral LD-50 between 50 and 500 mg/kg. Examples of toxicity level I and II chemicals frequently involved in child poisonings include chlorine bleach, flea and tick sprays for pets, and other pesticides. It has been estimated that about 300 level I products and 600 level II products are in use by the public.

A higher proportion of children with exposure to the more toxic products had serious medical outcomes. Children two years and under were most often poisoned from disinfectants and insecticides. Of 23 disinfectants studied 5 caused the most occurrences of child poisonings. The active ingredients among these included ammonium chloride, ethyl alcohol, phenylphenol, pine oil, and pyridine. One year old children had the most occurrences of poisoning (46%), two year olds the next (29%) and the older children had correspondingly less occurrences. Effects of the poisoning ranged most frequently from vomiting to eye irritation, respiratory problems, and throat and skin irritation.

Many unintentional pesticide poisonings and exposures to young children resulting in injury or death are preventable. Protective measures - such as substituting less lethal pesticides, reducing the concentration of the active ingredients, storage in safe containers in areas or at heights where they are not available to children, and improving packaging are recommended.

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