Childhood exposure to multiple persistent organic pollutants and midlife cognitive function.

Area of Science:

• Environmental Health
• Neuroscience
• Toxicology

Background:

• The long-term impact of early-life exposure to persistent organic pollutants (POPs) on adult cognitive function remains largely unexamined.
• This study investigates the relationship between childhood serum POP levels and cognitive abilities in midlife.

Purpose of the Study:

• To determine if childhood exposure to persistent organic pollutants (POPs) is associated with cognitive function in mid-adulthood.
• To identify specific POPs contributing to potential cognitive deficits.

Main Methods:

• A prospective cohort study involving 1304 children aged 3-18 years.
• Measurement of 18 serum POPs in childhood, including hexachlorobenzene (HCB), p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), and polychlorinated biphenyls (PCBs).
• Cognitive function in mid-adulthood assessed using the CANTAB computerized test battery, analyzing memory, learning, working memory, reaction time, and information processing. A weighted quantile sum (WQS) regression was used to derive a POP mixture index.

Main Results:

• An increase in the POP mixture index was associated with lower memory and learning abilities in midlife (β = -0.086, 95% CI: -0.160 to -0.011).
• This cognitive decline was equivalent to approximately 1.7 years of additional aging.
• The POP mixture was predominantly composed of hexachlorobenzene (HCB), p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), and polychlorinated biphenyl 99 (PCB99).

Conclusions:

• Childhood exposure to elevated levels of multiple POPs, particularly HCB, p,p'-DDT, and PCB99, is linked to impaired memory and learning in midlife.
• This association is independent of adult POP exposure, suggesting a critical window of vulnerability in early life.