The "obesity epidemic" is constantly in the news. This year's CDC figures show that 1 in 88 children in the U.S. is on the autism spectrum. Childhood cancers and neurodevelopmental delays are on the rise.
Scientific studies show that many of these health conditions can be linked to exposures to environmental contaminants such as pesticides, and new research is finding that exposures occurring as far back as three generations can cause adverse health conditions today.
In this latest study, published in Proceedings of the National Academy of Sciences, researchers exposed mice to a single dose of a commonly used fungicide, vinclozolin. The exposure altered the way certain genes were activated, and this change was passed on to future generations of mice — causing many of them to develop mental disorders and obesity.
Study author David Crews explains:
It's as if the exposure three generations before has reprogrammed the brain so it responds in a different way to a life challenge.
Growing evidence, range of effects
This study comes on the heels of earlier research indicating that exposures to toxins found in commonly used pesticides, household chemicals and plastics can cause reproductive damage in successive generations. The field of epigenetics, which studies heritable changes in gene expression, is shining a light on more such examples of diseases which are a result of chemical exposures occurring generations ago.
A recent article in Environmental Health Perspectives states:
Today, a wide variety of illnesses, behaviors and other health indicators already have some level of evidence linking them with epigenetic mechanisms, including cancers of almost all types, cognitive dysfunction, and respiratory, cardiovascular, reproductive, autoimmune and neurobehavioral illnesses.
The known and suspected drivers behind epigenetic processes listed include pesticides, heavy metals and tobacco, among other substances.
Putting future generations at risk
This growing body of evidence is particularly resonant in the case of pesticides and chemicals that persist for decades in the environment. Known as "persistent organic pollutants" or POPs, long-lasting pesticides like DDT and endosulfan have been harming communities across the globe for decades.
Now we understand that the health impacts of these POPs pesticides may be passed on through epigenetic changes to future generations even after these pesticides have degraded and are no longer persistent in the environment. PAN Campaign Coordinator Medha Chandra sees this as yet another reason to shift away from reliance on dangerous pesticides:
This profoundly disturbing knowledge is a call to action. When we protect today's children and communities from pesticide exposure, we are also protecting the health of future generations.