Category: Health

Organophosphate Pesticides

What are Organophosphate Pesticides?

  • Organophosphate-based pesticides (“OP pesticides”) are the most commonly used form of agricultural insecticide in the U.S., including on fruits and vegetables. Recent reporting indicates that the use of OP pesticides in the U.S. is now in decline.
  • OP pesticides have been banned for home use in the U.S. and have attracted significant attention for their known harmful effects on the nervous system. OP pesticides were developed after World War II, based on wartime nerve gases.
  • It is thought that OP pesticides break down quickly when exposed to light and air, and so are favored over organochlorine pesticides (OC pesticides) like DDT. However, it is not known whether OP pesticides ever degrade fully and they have been detected in soil and drinking water long after application.
  • Furthermore, exposure to large amounts of OP pesticides is more harmful to human health than the same large amount of OC pesticides.

Findings from CERCH Research on Organophosphate Pesticides:

From the CHAMACOS Health Outcomes Study –

Mothers’ exposure to organophosphate (OP) pesticides during pregnancy is associated with:

  • Shorter duration of pregnancy.
  • Poorer neonatal reflexes.
  • Lower IQ and poorer cognitive functioning in children.
  • Increased risk of attention problems in children.

From the CHAMACOS Functional Genomics PON1 Study –

The PON1 gene, and the PON1 enzyme that it codes for, impact the body’s ability to detoxify organophosphate pesticides and eliminate them from the body.

  • Children, particularly newborns, have much lower levels of PON1 enzyme levels and activities than adults and may therefore be more susceptible to pesticide exposures.
  • PON1 enzyme activities were elevated in mothers during pregnancy and at the time of delivery compared to when they were not pregnant. (Go to Publication)

Genetic Control of PON1 Enzyme Levels and Activity:

  • PON1 polymorphisms may affect susceptibility to pesticide exposures:
    • The Genetic polymorphism PON1-108 was associated with PON1 levels.
    • The Genetic polymorphism PON1-192 was associated with PON1 activity.
  • Genetic control of PON1 enzymatic activity is different in children compared to adults.
  • The relative influence of genetic polymorphisms on PON1 phenotypes (enzyme quantity and activity) varied in mothers and their children.

Associations of PON1 with Health Outcomes:

  • Certain PON1 genetic polymorphisms were also associated with:
    • Shorter gestational duration (Go to Publication)
    • Smaller head circumference (Go to Publication)
    • Lower mental and psychomotor development (MDI & PDI) scores. (Go to Publication)
    • Increased risk of pervasive development disorder (PDD), a category of developmental disorders that include several autism spectrum disorders. (Go to Publication)

From the CERCH Environmental Exposures Studies

General

  • Eating organically-grown fruits and vegetables reduces exposure compared with eating conventionally-grown produce.*
  • Wearing protective gloves and clothing during agricultural work greatly reduces exposure.

Also Read: The CHAMACOS Study

Maternal Organophosphate Pesticide Metabolites in Urine

  • The CHAMACOS cohort of pregnant women have levels of organophosphate (OP) pesticide metabolite levels in urine 30-40% higher than U.S. national reference levels reported for women of child-bearing age (18-40 yrs old) by NHANES.
  • Based on cumulative OP pesticide dose estimates, 14.8% of pregnant women in the CHAMACOS cohort may exceed health-based exposure benchmarks
  • We also measured 34 metabolites of current-use pesticides and other precursor compounds in urine samples collected from women twice during pregnancy.
  • Detected metabolites may be related to home or agricultural pesticide use in the Salinas Valley, household products, and other sources of chlorinated phenols.
  • More than 78% of CHAMACOS women had detectable levels of at least one OP pesticide-specific metabolite, and > 30% had two or more.
  • The 95th percentile values of six of the most commonly detected compounds were significantly higher among the CHAMACOS women compared to U.S. national reference levels for pregnant women after controlling for age, race, socioeconomic status, and smoking.
  • Findings suggest that the CHAMACOS cohort has an additional burden of pesticide exposure compared with the national sample, possibly from living and/or working in an agricultural area.

Organophosphate Pesticide Exposure Modeling

  • Biomarker comparisons and model results showed that women in the CHAMACOS cohort have a slightly but significantly higher intake of OP pesticides compared to women in the US general population as reported in NHANES.
  • Results from this comparison suggest that diet is the common and dominant exposure pathway in both populations.

Further Reading: ‘A Watchful Eye on Farm Families’ Health’

Teen Study Reveals Dangerous Chemicals in Cosmetics

In Salinas, California, home to a booming agricultural industry and stark economic contrast between the south and east sides of town, a group of teenagers became involved in a University of California, Berkeley research study involving chemicals in cosmetics.

The main chemicals the young students were focused on are a kind called “endocrine disruptors,” which can be found in many of the commercially available cosmetic products in large retail stores like Wal-Mart.

But less than 20% of cosmetic chemicals have been assessed for safety, meaning it’s difficult to tell what effects these chemicals have on the body—especially when applied daily.

California Endowment reporting fellow Vanessa Rancaño reports on the teen researchers who helped bring new light to an ignored problem in the word of makeup.

The UC Berkeley Center for Environmental Research and Children’s Health (CERCH) announces the release of a new training course for California’s licensed pest management professionals serving schools and child care.

You can go directly to the course here: http://www.ipm.ucdavis.edu/ training/school-and-child- care-ipm.html

New changes to the Healthy Schools Act in 2015 strongly encourage schools and child care providers to use the least toxic methods to control pests. 

Called integrated pest management, or IPM, these methods aim to prevent pests. 

When there is a problem, pesticides are used as a last resort, and, baits or traps are preferred over sprays and foggers.

The CHAMACOS Study

The CHAMACOS Study is a longitudinal birth cohort study examining chemicals and other factors in the environment and children’s health.

In 1999-2000, we enrolled 601 pregnant women living in the agricultural Salinas Valley.

We are following their children through age 16 to measure their exposures to pesticides and other chemicals and to determine if this exposure impacts their growth, health, and development.

In 2010-2011 we enrolled 300 additional 9-year-old children into the cohort and will be following them also until age 16. 

“C.H.A.M.A.C.O.S.” stands for Center for the Health Assessment of Mothers and Children of Salinas, and also means “little children” in Mexican Spanish.

The CHAMACOS Study investigates:

  • How children are exposed to pesticides and other environmental chemicals
    • Exposure Assessment Studies
  • How these exposures are related to children’s growth, neurodevelopment, and health
    • Health Outcomes Studies
  • The mechanisms by which these exposures may impact health
    • Epigenetics Study
    • Functional Genomics (PON1) Study
  • Ways to reduce exposure to children and families
    • Community Outreach
    • Intervention Studies

The CHAMACOS Study is a Community-University partnership modeled on the tenets of community-based participatory research.

Community Partners:

Reduced breathing capacity in kids linked to early pesticide exposure

Taking a deep breath might be a bit harder for children exposed early in life to a widely used class of pesticides in agriculture, according to a new paper by UC Berkeley researchers.

The greater the pesticide exposure, the smaller the lungs, a new study finds.

A new study has linked the levels of organophosphate pesticide metabolites in the urine of 279 children living in California’s Salinas Valley with decreased lung function.

Also Read: What is Wellness in Early Childhood

Each tenfold increase in concentrations of organophosphate metabolites was associated with a 159-milliliter decrease in lung function, or about 8 percent less air, on average, when blowing out a candle.

The magnitude of this decrease is similar to a child’s secondhand smoke exposure from his or her mother.

The findings, published today in the journal Thorax, are the first to link chronic, low-level exposures to organophosphate pesticides – chemicals that target the nervous system – to lung health for children.

“Researchers have described breathing problems in agricultural workers who are exposed to these pesticides, but these new findings are about children who live in an agricultural area where the organophosphates are being used,” said study senior author Brenda Eskenazi, a professor of epidemiology and of maternal and child health. “This is the first evidence suggesting that children exposed to organophosphates have poorer lung function.”

The children were part of the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), a longitudinal study in which the researchers follow children from the time they are in the womb up to adolescence.

The researchers collected urine samples five times throughout the children’s lives, from age 6 months to 5 years, and measured the levels of organophosphate pesticide metabolites each time.

When the children were 7 years old, they were given a spirometry test to measure the amount of air they could exhale.

The study accounted for other factors that could affect the results, such as whether the mothers smoked, air pollution, presence of mold or pets in the home and proximity to highways.

“The kids in our study with higher pesticide exposure had lower breathing capacity,” said study lead author Rachel Raanan, who conducted the research while she was a postdoctoral scholar in Eskenazi’s lab.

“If the reduced lung function persists into adulthood, it could leave our participants at greater risk of developing respiratory problems like COPD (chronic obstructive pulmonary disease).”

The study did not examine the pathways for the children’s exposure to pesticides, but the researchers did recommend that farmworkers remove their work clothes and shoes before entering their homes.

They also suggested that when nearby fields are being sprayed with pesticides, children be kept away and, if indoors, windows should be closed.

Pesticide exposure can also be reduced by washing fruits and vegetables thoroughly before eating.

“This study adds exposure to organophosphate pesticides to the growing list of environmental exposures – including air pollution, indoor cook-stove smoke, and environmental tobacco smoke – that could be harmful to the developing lungs of children,” said Raanan. “Given they are still used worldwide, we believe our findings deserve further attention.”

The authors noted that although organophosphate pesticides are still widely used, most residential uses of organophosphate pesticides in the United States were phased out in the mid-2000s.

In California, use of organophosphates in agriculture has also declined significantly from 6.4 million pounds in 2000, when the study began, to 3.5 million pounds in 2013, the year with the most recent pesticide use data.

Just last month, the U.S. Environmental Protection Agency proposed eliminating all agricultural uses of chlorpyrifos, one of the most heavily used organophosphates, and others are also under evaluation, steps that will continue the trend of declining use.

“Chronic obstructive pulmonary disease is an increasing cause of death around the world,” said study co-author and pulmonary specialist Dr. John Balmes, a UC Berkeley professor of environmental health sciences with a joint appointment at the UC San Francisco School of Medicine.

“Since we know that reduced lung function increases the risk for COPD, it is important to identify and reduce environmental exposures during childhood that impair breathing capacity.”

This work was supported by the National Institute of Environmental Health Sciences and the EPA.

Raanan’s fellowship was supported by the Environment and Health Fund in Israel.