biostudies-literatureKhan ADefense Advanced Research Projects AgencyNordForsk Fund (DK)NHLBI NIH HHSNIMH NIH HHSNational Institutes of Health (US)NordForskNovo Nordisk FondenLundbeck FoundationLiz and Kent Dautene3000353https://www.ebi.ac.uk/biostudies/studies/S-EPMC6701746biostudies-literatureUnknown17(8)The search for the genetic factors underlying complex neuropsychiatric disorders has proceeded apace in the past decade. Despite some advances in identifying genetic variants associated with psychiatric disorders, most variants have small individual contributions to risk. By contrast, disease risk increase appears to be less subtle for disease-predisposing environmental insults. In this study, we sought to identify associations between environmental pollution and risk of neuropsychiatric disorders. We present exploratory analyses of 2 independent, very large datasets: 151 million unique individuals, represented in a United States insurance claims dataset, and 1.4 million unique individuals documented in Danish national treatment registers. Environmental Protection Agency (EPA) county-level environmental quality indices (EQIs) in the US and individual-level exposure to air pollution in Denmark were used to assess the association between pollution exposure and the risk of neuropsychiatric disorders. These results show that air pollution is significantly associated with increased risk of psychiatric disorders. We hypothesize that pollutants affect the human brain via neuroinflammatory pathways that have also been shown to cause depression-like phenotypes in animal studies.PLoS biologyEnvironmental pollution is associated with increased risk of psychiatric disorders in the US and Denmark.PMC6701746project 75007R01 HL122712giftR01HL122712, 1P50MH094267, and U01HL108634-0175007P50 MH094267U01 HL108634NNF17OC0027864W911NF1410333R248-2017-2003Brandt JGeels CPedersen CBRzhetsky AKhan ALandecker HPlana-Ripoll OAntonsen SSullivan PFfalseEnvironmental pollution is associated with increased risk of psychiatric disorders in the US and Denmark.The search for the genetic factors underlying complex neuropsychiatric disorders has proceeded apace in the past decade. Despite some advances in identifying genetic variants associated with psychiatric disorders, most variants have small individual contributions to risk. By contrast, disease risk increase appears to be less subtle for disease-predisposing environmental insults. In this study, we sought to identify associations between environmental pollution and risk of neuropsychiatric disorders. We present exploratory analyses of 2 independent, very large datasets: 151 million unique individuals, represented in a United States insurance claims dataset, and 1.4 million unique individuals documented in Danish national treatment registers. Environmental Protection Agency (EPA) county-level environmental quality indices (EQIs) in the US and individual-level exposure to air pollution in Denmark were used to assess the association between pollution exposure and the risk of neuropsychiatric disorders. These results show that air pollution is significantly associated with increased risk of psychiatric disorders. We hypothesize that pollutants affect the human brain via neuroinflammatory pathways that have also been shown to cause depression-like phenotypes in animal studies.2019-01-01T00:00:00Z2019 Aug2025-04-19T19:48:42.262Z2019-09-24T07:04:39ZS-EPMC67017463143027110.1371/journal.pbio.3000353