06
Apr
Living Within 2.5 Miles of Chemical Farming Increases Risk of Childhood Brain Tumors
(Beyond Pesticides, April 6, 2021) Pregnant women living within 2.5 miles of agricultural pesticide applications have an increased risk that their child will develop central nervous system (CNS) tumors, according to a study published in the journal Environmental Research by a team at University of California, Los Angeles. The results are particularly concerning as it reveals that individuals do not have to be in close contact with pesticides for risky, health-harming exposures to occur. “This transition from farmland to residential neighborhoods is abrupt across California, and, of course, constantly changing as farmland is developed,” said study co-author Myles Cockburn, PhD. “The simplest way to mitigate these risks is by reductions in exposure to pesticides, through restrictions to aerial spraying and air blast that lead to increased drift, and by farming methods that decrease reliance on pesticides.”
Researchers note that the present study is unique in that it was able to pinpoint the specific pesticides related to the development specific types of tumors. To make these determinations, scientists made use of California’s Cancer Registry records. Diagnosed children aged 0-5 were matched to maternal residences where pesticide applications were made within 4000 meters (~2.5 miles). Pesticide application records were obtained from data recorded by California’s public agencies, as California is one of the only states that require pesticide use reporting to a centralized database. Researchers adjusted for a number of confounders and matched each cancer case selected with twenty controls in order to increase the statistical power of the findings.
Results show that some pesticides increase the risk of certain childhood CNS tumors by 2.5 times compared to an unexposed child. For astrocytoma tumors, the use of the pesticides bromacil, thiophanate-methyl, triforine, and kresoxim-methyl increased risk of tumor development. Medulloblastoma was associated with the use of chlorothalonil, propiconazole, dimethoate, and linuron. Development of ependymoma was linked to nearby use of thiophanate-methyl. In sum, the pesticides chlorthalonil, bromacil, thiophanate-methyl, triforine, kresoxim-methyl, propiconazole, dimethoate, and linuron were all linked to elevated rates of a CNS tumor.
These data are much more precise than the findings of previous studies, which generally group pesticide use into broad categories based on type (herbicide, insecticide, fungicide, etc.) or chemical class. “This study is the first, to our knowledge, to estimate effects for a large number of specific pesticides in relation to CNS tumor subtypes,” said Julia Heck, PhD, study coauthor. “Our results suggest that exposure to specific pesticides may best explain the results of previous studies that reported relationships between broader pesticide types and central nervous system tumors.”
There is no shortage of studies linking pesticide use to diseases in pregnant women and children. A 2013 study published in Cancer Causes and Control found that women exposed to termite pesticides within a year of pregnancy were nearly twice as likely to have a child develop a brain tumor. Research published in Environmental Health in 2015 ties agricultural crop density closely with the development of leukemia and CNS cancers in children. A 2017 study published in the International Journal of Cancer associates the residential use of pesticides with 1.4 times increased risk of developing a brain tumor by age 15. And a study published in 2020 in Cancer Epidemiology found that pesticide use during pregnancy was associated with childhood development of the Wilms’ tumor of the kidney.
The present study, which found the highest rates of CNS tumors in Hispanic and non-Hispanic white children, reveals cause for concern to all individuals throughout the country that may live near a chemical farming operation. “California’s agricultural work force numbers more than 800,000, according to state estimates,” said Christina Lombardi, PhD, a co-author and epidemiologist with the Samuel Oschin Comprehensive Cancer Institute at Cedars-Sinai Medical Center in Los Angeles. “In addition to the negative health effects of pesticides on workers there are large numbers of pregnant women and young children living adjacent to treated fields who may experience detrimental health effects as well.”
The power of the present study is that is highlights the real risks from specific pesticide active ingredients. While the solution – eliminating the use of these toxic substances – remains the same, this granular data should provide regulators and policymakers greater confidence in decisions to restrict or eliminate use.
As the authors note, it is imperative for the future of our health to embrace farming systems that do not rely on the use of hazardous, cancer-causing chemicals. Children diagnosed with CNS tumors are not only a tragedy for the families that must care of them – these heartbreaks affect us all – from the costs of recovery and delayed development to public health infrastructure and special classes in school, and the loss of earnings over a lifetime. One study published in January of 2020 found that exposure to environmental chemicals since the turn of the century has resulted in trillions of dollars of lost economic activity. And beyond the dollars and cents, contributions to art, culture, or technology that humanity as a whole are lost when a young life’s potential is stolen by the use of chemicals that are known to be unnecessary.
Hazardous synthetic pesticides are not permitted under organic farming standards. It is evident that the more we delve into the details of synthetic pesticide use, the more problems are raised, and the stronger the argument becomes for a broadscale transition to organic agriculture.
Help encourage this transition by growing the organic marketplace and purchasing organic products whenever possible. For those in agricultural areas, it would be prudent to consider one’s proximity to chemical farming if considering a child. For more information on the links between pesticide use and our health, see Beyond Pesticides Pesticide-Induced Diseases Database. And see the newly revamped Children and Schools webpage for more information on the hazards of pesticides to children, and how they can best be protected where they learn and play.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: UCLA Fielding School of Health press release, Environmental Research
