Pesticide Residues
Organophosphates, glyphosate, neonicotinoids
What is it?
Pesticide residues are traces of agricultural chemicals remaining on or in food after conventional farming. The three most significant classes in dietary exposure are organophosphates (nerve-agent derivatives used as insecticides), glyphosate (the most widely used herbicide globally, known as Roundup), and neonicotinoids (systemic insecticides that persist in plant tissue). Unlike surface contaminants that can be washed off, systemic pesticides are taken up into plant cells and cannot be removed by washing. The EWG Dirty Dozen list, published annually, identifies which crops carry the highest residue loads.
What it does to your body
Neurodevelopmental harm
Prenatal and childhood exposure to organophosphates is among the most robustly documented environmental exposures linked to lower IQ and ADHD traits in children.
Parkinson's disease
Epidemiological studies show a consistent association between pesticide exposure, particularly rotenone and paraquat, and Parkinson's disease.
Cancer
Glyphosate is classified as a probable human carcinogen by the IARC (Group 2A). Chlorpyrifos and several other organophosphates are linked to non-Hodgkin lymphoma and childhood leukaemia.
Gut microbiome disruption
Glyphosate inhibits the shikimate pathway used by gut bacteria, potentially contributing to dysbiosis at residue levels documented in food.
Hormonal disruption
Many pesticide compounds interfere with thyroid, oestrogen and androgen signalling at residue levels found in food.
How widespread is the problem?
The EWG finds detectable pesticide residues on approximately 70% of non-organic produce tested annually. The CDC detects pesticide metabolites in the vast majority of Americans tested. Children eating conventional diets have significantly higher organophosphate metabolite levels than those eating predominantly organic diets.
Where it hides in your home
Key research
IARC Monograph 112: Glyphosate
International Agency for Research on Cancer classified glyphosate as a probable human carcinogen (Group 2A), based on sufficient animal evidence and limited human evidence.
Rauh et al. Prenatal Chlorpyrifos and Neurodevelopment
Columbia University study demonstrating structural brain changes in children with higher prenatal chlorpyrifos exposure, including reduced cortical thickness in areas governing attention and memory.
EWG Shoppers Guide to Pesticides in Produce
Annual analysis of USDA pesticide testing data, identifying crops with highest and lowest residue levels. Finds residues on over 70% of non-organic produce.
Most pesticide metabolites are excreted within days. However, people who eat conventional diets maintain chronically elevated levels. Switching to organic produce for the highest-residue crops produces measurable reductions in urinary pesticide metabolites within days.