“…For example, the Canadian Study of Health and Aging, which followed individuals over a period of 10 years, found no significant association between PCB or OCP levels and incident dementia or AD risk; however, elevated levels of PCBs 118, 153, 156, and 163 and OCPs, dichlorodiphenyltrichloroethane and p,p'‐DDE, were significantly associated with lower cognitive performance scores 135 . Work in agricultural sectors also did not confer increased risk for AD in a population with dementia, 132 but a study of trichlorophenol levels in the USA revealed that individuals with higher urinary levels of the agricultural chemical, 2,4,6‐trichlorophenol, had increased risk of AD and of all‐cause mortality 134 . Metals exposure studies, in contrast, support increased AD risk from higher aluminum, cadmium, chromium, copper, and iron 130,136 .…”