PBDE (chemicals from Flame Retardants) exposure was the greatest contributor to intellectual disability burden, resulting in a total of 162 million IQ points lost and over 738,000 cases of intellectual disability.
Trends in neurodevelopmental disability burden due to early life chemical exposure in the USA from 2001 to 2016: A population-based disease burden and cost analysis
Abigail Gaylord, Gwendolyn Osborne, Akhgar Ghassabian, Julia Malits, Teresa Attina, Leonardo Transande; Molecular and Cellular Endocrinology; Online: 14 January 2020. doi 10.1016/j.mce.2019.110666.
Endocrine disrupting chemicals are known to cause neurodevelopmental toxicity through direct and indirect pathways. In this study we used data from the National Health and Nutrition Examination Surveys, along with known exposure-disease relationships, to quantify the intellectual disability burden attributable to in utero exposure to polybrominated diphenyl ethers (PBDEs commonly known as Flame Retardants), organophosphates, and methylmercury and early life exposure to lead. We also estimated the cost of the IQ points lost and cases of intellectual disability. PBDE exposure was the greatest contributor to intellectual disability burden, resulting in a total of 162 million IQ points lost and over 738,000 cases of intellectual disability. This was followed by lead, organophosphates, and methylmercury. From 2001 to 2016, IQ loss from PBDEs, methylmercury, and lead have decreased or remained stagnant. Organophosphate exposure measurements were only available up to 2008 but did show an increase in organophosphate-attributable IQ loss. Although most of these trends show benefit for children’s neurodevelopmental health, they may also point towards the use of potentially harmful substitutions for chemicals that are being phased out.
Combined exposure to heavy metals and pesticides can lead to more severe effects on human health compared to their individual effects.
Synergistic effects of heavy metals and pesticides in living systems
Singh N, Gupta VK, Kumar A, Sharma B. Synergistic effects of heavy metals and pesticides in living systems. Frontiers in Chemistry. 2017;5:70.
Combined exposure to heavy metals and pesticides can lead to more severe effects on human health compared to their individual effects. This review reports that various combinations (pesticides combined with pesticides, pesticides combined with heavy metals, and heavy metals combined with heavy metals) all act synergistically and exhibit more toxicity than a single toxin alone. More work is needed to study the biotransformation of heavy metals and pesticides in combination and the mechanisms by which they affect toxicity.