Childrens Health: Pesticides

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Childrens Health Pesticides Lactation

• Ana Maria Osorio, MD, MPH
• Tel [phone], ext 117
• AnaMaria.Osorio_at_fda.gov

The conclusions and opinions expressed are those
of the author and do not necessarily represent
the views and policies of the US Food and Drug
Administration.
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Homes, children pesticides

• US residences have been shown to be contaminated
  with pesticides such as organophosphates (OP),
  carbamates, organochlorines (OC), pyrethroid and
  herbicides
• Children may be at increase risk 2nd relatively
  higher intake of food, water and air per unit of
  body weight
• Also, children are developmentally immature and
  may be more susceptible

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Children routes of exposure

• Young children can be exposed to pesticides
  during normal oral exploration of their
  environment and their proximity to potentially
  contaminated floors, surfaces and air.
• Kids in ag areas may be exp to higher pesticide
  levels 2nd to pesticides tracked into home by
  household members, pesticide drift, breast milk
  from FW mother or playing in nearby fields

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Breast milk and pesticides

• Pesticides in the environmental can be stored in
  the mothers body tissue or secondarily present
  via current diet, occupational exposure or
  personal habits
• Exposure via breast milk can be substantial,
  especially when mother has significant ongoing
  exposure or has accumulated an usually high body
  burden of persistent pesticides
• OCs acquired from breast milk increases childs
  body burden for several years
• Decline of persistent OC residues in Western
  countries suggests that exposure through breast
  milk will also diminish
• Less persistent pesticides such as
  organophosphates can also be detected in milk
• Less information is available for currently used
  pesticides

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Organochlorines (OC) metabolites detected in
breast milk, US

• Aldrin
• Chordane
• DDT metabolites
• Dieldrin
• Heptachlor

• Hexachlorobenzene
• Hexachlorocyclohexane
• Mirex
• Nonachlor

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OC residues in breast milkfield study
difficulties (Harris, 2002)

• Reviewed existing studies to evaluate factors
  most likely to influence transfer of OC residues
  into breast milk
• External factors considered (these were evaluated
  as less influential)
• Diet
• Fish consumption
• Smoking
• Residence and/or occupation

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OC residues in breast milkfield study
difficulties (continued)

• Physiology and lactation influence considered
• Age (bioaccumulation over time in adipose tissue)
• Parity and/or length of previous lactation
  (lactation most likely to reduce stored
  concentrations in the body)
• Correlation with fat content of milk
• Body weight and mobilization of fat (fat
  mobilization one of most common reasons for
  transfer of OC into breast milk)
• Variable fat content of breast milk ? timing of
  sampling is likely to be critical in relation to
  interpretation of findings (important in
  comparing studies)

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HCH Hexachlorocyclohexane (lindane)DDT
1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethaneHCB
Hexachlorobenzene
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HCB Hexachlorobenzene HCH Hexachlorocyclohexa
ne (lindane)DDE 1,1-Dichloro-2,2-bis(p-chloroph
enyl)ethylene DDT 1,1,1-Trichloro-2,2-bis(p-chl
orophenyl)ethane
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Calculation of infant intake of contaminants

• Mean breast milk consumption
• (per kg body weight)
• (Mean breast milk consumed, ml / day) x
• ( Fat) x (Infant age, months)
• -----------------------------------------------
• (Infant weight, kg)

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HCH Hexachlorocyclohexane (lindane)
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International levels of DDE in breast milk (mean
ug/g)
Banned in US in 1972
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Sweden Trend in levels of DDE in breast milk
(mean ug/g)
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Fetal exposure to DDE was associated with delay
in mental psychomotor development at 13 months.
Long-term breast feeding found to be beneficial
(Ribas-Fito 2003)
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OP exposure among children

• Low-level exposure to OPs affects
  neurodevelopment and growth in developing animals
• National biomonitoring ,which includes pregnant
  women and children, shows widespread OP exposure
  in US population
• OPs eliminated from body after 3-6 days so
  widespread detection indicates continuous
  exposure
• Children of FWs more likely than non-FW children
  to be exposed to pesticides

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CDC - Biomonitoring

• 2nd National Report on Human Exposure to
  Environmental Chemicals, Jan 2003, CDC
• US population sample (N1949)
• Age 6-59 years
• Collection period 1999-2000
• Analysis for 6 metabolites of OPs
  DMP, DMTP, DMDTP, DEP, DETP, and DEDTP

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DMTP - Geometric mean (ug/gram of creatinine)
with upper and lower 95 confidence intervals.
US population sample (N1948), age 6-59 years,
time period 1999-2000.
Distribution by age group
Distribution by gender
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DEP - Geometric mean (ug/gram of creatinine)
with upper and lower 95 confidence intervals.
US population sample (N1949), age 6-59 years,
time period 1999-2000.
Distribution by age group
Distribution by gender
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Studies looking at child exposure to pesticides
in FW community

• (Loewenherz 1997) Washington State 44 of kids
  of pesticide applicators and 27 of nonfarm,
  rural kids con detectable OP residues (especially
  true when living near orchards).
• (Curl 2002) Washington State elevated urinary
  OP metabolites for adult and child (age 2-6) from
  same household. Supports take-home exposure
  route.
• (Fenske 2002) Washington State Child urinary
  metabolites for chlorpyrifos and parathion were
  elevated in homes closer to pesticide treated
  farmland, 200 ft or 60 meters.

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California farm worker study (Castorina, 2003)

• 1999 2001, collected 3 spot urines from
  pregnant female (N 446) in longitudinal birth
  cohort study (California ag community)
• Test 6 metabolites analyzed in urine
• Used California Pesticide Use Report data to
  profile the mix of OPs used in this community
• CDC national biomonitoring data can be used as
  comparison values

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OP use in study community as kg of active
ingredient
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OP metabolites used in study
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Mean metabolite values for 446 women studied
(1,338 samples) mean values from CDC national
biomonitoring survey (for women age 2059, years
1999-2000)
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Final thoughts

• WHO position that breast feeding be done for 6
  months followed by gradual introduction of
  complementary foods for up to 2 years
• Emphasis should be on primary prevention in case
  of environmental and subsequent maternal milk
  contamination
• Breast milk exposure relatively minor in
  comparison to fetal route of exposure
• Benefits of continuing breast feeding need to be
  weighed against potential hazards from
  environmental contaminants