STAR

REPORT

Vol. 1 Issue 1 Oct. 1997 A product of the National Center for Environmental Research and Quality Assurance

The protection of children’s health is one of the highest priorities

of the Environmental Protection Agency

 Children face an array of complex environmental health threats. They are more

susceptible than adults to harmful health

effects from some chemicals, including

pesticides, because of their activities, and

because their small, developing bodies are

more sensitive to toxic stress. Because of

this, EPA has made a special commitment

to ensure that all children are protected

against harm from pesticides and other

chemicals.

 The exposure of children to pesticides

around their homes, and in public areas such

as schools, playgrounds or day care centers,

has been recognized as an important and

inadequately understood problem. In conducting a 1993 review of potential risks due to

pesticides in the diets of children, the National

Research Council (NRC) determined that

children, including infants, might be at greater

risk than adults from harmful effects that

pesticides can cause. Potential effects of

pesticides on people of any age include central nervous system damage, cancer and

respiratory illness. In addition, based on the

NRC report and other studies, EPA has taken

steps to ensure that necessary additional

testing will be undertaken to assess any special

vulnerability of children to pesticide effects on

development, the immune system, the reproductive system and the visual system.

 Several factors may contribute to increased

vulnerability of children to pesticides. The rapid

development and immaturity of their body organs and systems makes them more susceptible

than adults to toxic effects of any chemicals.

For example, children’s tissues may absorb chemicals more readily and be less able to break them

down, and their organ systems may be less effective at passing some chemicals out of the body.

CHILDREN’S EXPOSURE

TO PESTICIDES

U.S. EPA Office of Research

and Development’s Science

To Achieve Results (STAR)

Research in Progress
2

In addition, the amount of exposure to pesticides is quite different

for children than for adults, because of differences in physical environment, activities and diet. The

NRC study considered all of these

factors, and concluded that differences in exposure between adults

and children were more likely to

account for differences in risk than

were age-related differences in toxicity. Based on this, the NRC

strongly recommended research

to better understand the extent to

which children are exposed to pesticides.

 Responding to this need, EPA’s

major external research program,

Science to Achieve Results (the

“STAR program”) allocated funds

in fiscal year 1996 to research the

most urgent issues regarding exposure of children to pesticides.

The grants were awarded for three

year time periods. Resulting findings, along with the results of some

related research under other components of the STAR program, will

provide a far more comprehensive

understanding of children’s pesticide exposures. Research currently

underway in these STAR projects

is summarized in this report. Results will be presented in future

reports over the coming one to

three years, as findings are completed and peer reviewed.

Settings of Special Concern

 Greater exposures of children to

pesticides than is typical for the

general population may occur in

some settings. In some cases, but

not all cases, these settings involve

a disproportionate number of

people of disadvantaged socioeconomic groups, such as migrant

agricultural workers, or residents of

older urban public housing complexes. Settings of particular concern including the following:

Urban homes subjected to frequent applications of insecticides and/or rodenticides;

Homes of agricultural workers, or

other rural homes, where children may be exposed to contaminated clothing or skin of

adults, or to agricultural chemicals coming into the home in

other ways;

 Institutional settings such as day

care centers in which infants

and very young children have a

high degree of exposure to carpets and other surfaces that

may be treated with commercial pesticide applications; and

Homes with pets treated with pesticides to control fleas or other

pests, or that track in pesticides

from outside the home.

 Children’s Behavior

 Behavioral factors that can make

children, including infants, more

likely to be exposed to pesticides

include the following:

crawling, sitting and lying on contaminated surfaces such as carpets, floors and lawns;

transfers of contaminants from

objects or surfaces through directly mouthing hands, objects or plants, and ingesting

dust or soil,

greater time spent in household

gardens, or in private or public play areas treated with pesticides.

General Information: The Environmental Protection Agency’s STAR Research Program

Grants described in this report are part of EPA’s Science to Achieve Results (STAR) program, a major

research initiative designed to improve the quality of scientific information available to support environmental decision making. The STAR program is managed by EPA’s Office of Research and Development

(ORD) out of the National Center for Environmental Research and Quality Assurance. The program is

expected to fund approximately 200 new grants every year, with the typical grant lasting three years.

Funding levels vary from $75,000 to $500,000 per year, with FY 1997 funding levels expected to reach

over $100 million for grants to individual principal investigators or groups of investigators. Additional

STAR funds are provided for a number of Research Centers specializing in scientific areas of particular

concern to EPA, and for a fellowship program supporting graduate students conducting environmental

research.
3

STAR Research Focusing on Children’s Exposures to Pesticides

STAR research projects are collecting data on children's behavior and environment that will be used to

assess exposure and risk. The extensive environmental and biological sampling proposed in the field

studies will allow further refinement in sampling design, field study protocols, analytical techniques,

human activity databases, and data interpretation for exposure assessments. The studies are looking at all

types of exposure (touching, eating, crawling, etc.), and at seasonal and locational differences. When

considered along with improved information on differences in toxicities of pesticides between children and

adults, the improved exposure information will give a much more complete picture of the differences in

overall pesticide risks. This will support regulations and public education efforts that are more fully protective of children, for example through revised use restrictions and labeling requirements, and improved

training and public information materials.

Total Exposure Assessments

 Three research projects are focusing on children’s exposures in

urban, suburban and suburban

settings. A study led by the University of Minnesota (1) is assessing amounts of the principal types

of pesticide that children encounter through all “exposure routes”

(for example: touching surfaces

in homes, schools and day care

centers; from outdoor exposures;

secondary contamination from family members; and contamination

of foods or drinks.) The

study will compare exposures in three types of

neighborhood: central

city, suburban, and rural.

In Yuma County, Arizona, investigators from

the University of

Arizonia (2) are assessing exposures of the children of seasonal and migrant laborers to agricultural pesticides. These

families frequently live near the

edges of fields. In eastern and

western Washington state, the

University of Washington (3) is

assessing, on a comprehensive seasonal basis, children’s exposures to

organophosphorus pesticides.

These are of particular concern

because they are widely used, and

they can cause neurotoxic effects

with high exposures.

Exposures of Children to Pets’ Flea

Control Chemicals. Complete information is not currently available

on how much pesticide exposure

children may experience from pets

treated with flea control products.

These products often contain organophosphorus compounds,

which are more readily absored

into the body through ingestion,

or hand-to mouth contact, than

through skin contact alone. This

study will help to determine

whether there are greater exposures, and thus potential for

greater risks, to children than

adults, due to greater likelihood of

exposure through fur contact with

skin, transfers from hands to

mouth, etc.. A grant was awarded

in FY 1996 to researchers at Mississippi State University (4), who

are determining how much active

ingredient from the most common

types of flea product is transferred

to children through the kinds of

interactions that can occur with

family dogs.

Other Related STAR

Research

 In addition to the component of the STAR program exclusively focused

on children and pesticides,

several projects funded

through other components of the STAR program

will also contribute information about potential

pesticide exposure or effects in children.

 Potential Chromosome

Damage in Male Pesticide Applicators. In the “Environmental

Health” category of STAR research

studies, a grant has been awarded

to the University of California,

Riverside (5), for some relevant

laboratory studies of cell cultures,

and for field studies of male pesticide applicators. The study will

assess whether laboratory expo-
4

sures of human cells to cancer

causing chemicals, or exposures of

men to pesticides in agricultural

work settings, are associated with

chromosome damage in human

cells, including sperm or lymphatic

system cells. Findings of chromosome damage would not directly

demonstrate what health or fertility impacts might be resulting in

exposed men or their children. If

chromosome changes were found

in the laboratory studies with human cells, and were confirmed in

studies of exposed people (for example through “exposure marker”

techniques), it would suggest an

important need for comprehensive

health effects studies, to determine

what relationships there are between specific pesticide exposures,

chromosome effects, and health

effects in adults and their children.

Potential Endocrine Disruptor Effects due to Maternal Exposure

in Rats. Wildlife observations have

found a number of initially unexplained incidents of reproductive

disorders, deformities or other

health effects related to the animals’ endocrine (hormone) systems. Subsequent studies have

found that some of these effects

were caused by toxic chemicals in

the environment, some of them

pesticides. Concern has been

raised that similar effects may occur in humans exposed to endocrine disruptor chemicals, including some pesticides and their

breakdown products. The STAR

program includes a research area

devoted to laboratory and field

studies of potential endocrine

disruptor effects relevant to people

or wildlife.

 One of the studies is looking at

a pesticide that could pose risks to

children. In this case the concern

is based on potential exposures of

mothers, rather than exposure of

children due to their own activities. Mississippi State University

(6) is using laboratory studies to

assess the effects of the insecticide

methoxychlor, as well as the industrial chemicals PCBs. They are testing the hypothesis that exposures

of female rats to a breakdown

product of methoxychlor may result in exposures of the young during pregnancy or while

nursing, thereby causing

abnormal sex hormone

levels and developmental

abnormalities in the

young as they mature. Because exposures tested will

include low levels that

could occur in the environment, findings of

harmful effects in rats

would indicate a possibility of risks to humans due

to maternal exposures.

This would indicate a need

for more work to thoroughly assess possible human exposure, and for

consideration of the new

information in regulating

insecticide uses.

Households’ Choices in

Chemical Uses for Gardening and Landscaping. One of the less well

known aspects of pesticide

exposure is the ways that

families use pesticides in

home gardening, and the

information people take
5

into account in making

choices about home chemical use. Under a component

of the STAR program devoted

to socio-economic research,

investigators at the University of California, Berkeley

(7), are studying factors that

affect the choices families

make in garden landscaping

and chemical use. The study

will assess which types of garden and landscape are chosen based on maintenance

time and costs, and whether

having children in the household affects uses of garden

pesticides. Results will be useful in evaluting regulatory, labeling, and public education

strategies for reducing risks.

 Related research relevant to

children’s exposures to pesticides

is also conducted directly in the

laboratories of EPA’s Office of Research and Development (ORD).

The Agency’s historical work on

pesticides and human development was summarized in a 1995

EPA report, “Pesticides in the Diets

of Infants and Children”. EPA’s

principal current research in this

area is through the “National Human Exposure Assessment” program (NHEXAS), being performed

by EPA/ORD, academic and other

research institutions, and other federal agencies. Also, EPA is conducting special regional studies

(complementing programs associated with the North American Free

Trade Agreement), assessing

children’s exposures to pesticides

in U.S.-Mexican border areas.

There is on-going coordination beFind Out More About the STAR Research Program

tween the STAR research projects

conducted by external scientists

and EPA’s in-house research. In

addition, STAR researchers and EPA

researchers are coordinating with

research by state health agencies.

Further information on the STAR program is available from

the following sources:

Internet Website, managed by the ORD National Center for Environmental Research and Quality Assurance (NCERQA):

URL: http://www.epa.gov/ncerqa

Mailing Address:

Office of Research and Development

National Center for Environmental Research and Quality

Assurance

Office of the Director (8701 R)

401 M Street

Washington, DC 20460

Or, use the Telephone Hotline, 1-800-490-9194, to leave messages and receive auto faxes of announcements.

Related Research of EPA’s In-House Laboratories
 Specific Research Projects Described in This Report

4) Assessing Levels of Organophosphorus Insecticides Which

Could Expose Children from

Pets Treated with Flea Control

Insecticides. College of Veterinary Medicine, Mississippi State University.

5) Development of Molecular

Cytogenetic Techniques to Detect Chromosomal Aberrations

in Human Sperm and Lymphocytes. University of California, Riverside.

6) Biochemical and Reproductive Effects of Gestational/Lactational Exposure to PCB's with

Respect to Endogenous Sex Steroids and the Proestrogen,

Methoxychlor. Mississippi

State University.

7) The Microeconomy of

Chemical Use on Residential

Landscapes. University of

California, Berkeley.

1) Measuring and Apportioning Children's Exposure to Pesticides in Urban, Suburban,

and Rural Communities.

School of Public Health,

University of Minnesota.

2) Exposure of Children to Pesticides in Yuma County.

Arizona College of Medicine, University of Arizona.

3) Total Organophosphorus

(Op) Pesticide Exposure among

Children in Urban and Rural

Environments. Department

of Environmental Health,

University of Washington.

United States

Environmental Protection Agency

Mail Code 8701R

Washington, D.C. 20460

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