Many people know that being exposed to pesticides can have a negative effect on their health and, this is especially true for expectant mothers. Doctors often warn pregnant women against using or being exposed to certain chemicals, but until now not much has been said about whether these pesticides can have differing effects depending on the sex of the child.
A new study shows prenatal exposure to pesticides affects boys’ brains more than girls.’ Columbia University researchers at the Center for Children’s Environmental Health analyzed data from a group of over 300 mother-child pairs enrolled in an ongoing study of environmental exposures, which included measuring levels of the pesticide chlorpyrifos in umbilical cord blood. Chlorpyrifos has been banned for residential use since 2001, yet is still widely used as an insecticide in agriculture.
Published in the journal Neurotoxicology and Teratology, the new study includes children who were born in New York City before and slightly after the 2001 chlorpyrifos restrictions. When the children were three-years-old, the researchers studied how well the mothers nurtured and stimulated them educationally, to account for any effect parental nurturing may have on the children’s development. At age seven, the children’s IQ was tested through a range of examinations, including short-term memory tests. Those children with higher trace amounts of chlorpyrifos in their umbilical cord blood showed a delay in mental and motor skill development, as well as reduced working memory and IQ scores. Interestingly, boys in the study averaged three points lower on their memory tests than the girls with similar exposure levels.
While this New York City study is the first of its kind to show a gender difference in the consequences of chlorpyrifos exposure, a previous study of farmworker children in the Salinas Valley in California showed a seven-point drop in IQ for children of mothers who had the highest organophosphate pesticide exposure, compared with children of mothers with the lowest exposures.
Why chlorpyrifos might affect boys more than girls is not fully understood, but a 2012 study of rats found the pesticide reduced testosterone, which has a critical role in male brain development. Endocrine disruptors, or chemicals in the environment that change the way hormones behave inside our bodies, can have serious implications for developing children’s bodies. Hormones are chemicals that transport messages between cells and control the delicate balance of our growth, our immune system, our development, and metabolism, among many other things. Interrupting or changing the chemicals that precariously balance the functions of our bodies can have severe consequences.
Inner-city children born much after the ban of residential use for chlorpyrifos will likely not experience those long-lasting health problems, since they will not be exposed to this pesticide. Farmworker children, however, are not as lucky. Annually, more than 10 million pounds of chlorpyrifos continues to be applied to agricultural fields with crops such as corn, cotton, citrus and nut trees, alfalfa, grapes, and others.
Farmworker women typically continue working in the fields during pregnancy. Many can’t afford not to work and are often unaware of the risk they are putting themselves and their children in. After birth, farmworker children are also exposed to these endocrine disrupting chemicals in their homes through pesticide drift and indirect contact, such as hugging their parents whose skin and clothing may be contaminated by pesticides after a long day of work. Children are also exposed to these dangerous chemicals directly as they themselves work in agricultural fields.
AFOP’s Health & Safety Programs LEAF (Limiting Exposures Around Families) curriculum teaches farmworkers simple steps to prevent exposing their families to these harmful pesticides. Project LEAF seeks to mitigate and increase awareness of these take home exposure risks to families through a training curriculum and other educational materials. For more information, please contact Levy Schroeder at Schroeder@afop.org.