Paternal occupational lead exposure and offspring risks for schizophrenia.
This register-based cohort study investigated whether paternal occupational exposure to inorganic lead was related to offspring risk for schizophrenia spectrum disorder (SSD). Exposed men (n=11,863) were identified from blood lead measurements taken at the Finnish Institute of Occupational Health in 1973-1983. Data on mothers and their offspring born from 1972-1984 were obtained from the national Population Information System. Two population comparison offspring for each exposed offspring were matched on date of birth, sex and area (n=23,720). SSD cases were identified from The Finnish Hospital Discharge Register. Hazard ratios of SSD between exposed groups were analyzed using conditional proportional hazards regression, adjusted for parental history of psychoses, parental ages, language of offspring, father's employment, and father's self-employment. After 26-38years of follow up, there were no significant differences in the incidence of schizophrenia, either between the offspring of exposed (188/11,863; 1.6%) and unexposed fathers (347/23,720; 1.5%) or based on blood lead levels (adjusted hazard ratios (aHR): 0.97, CI 0.52-1.83, 1.25, CI 0.85-1.82, 0.90, CI 0.54-1.49, and 1.38, CI 0.65-2.92 for lead categories <0.5, 0.5-0.9, 1.0-1.4, and ≥1.5μmol/L, respectively, as compared to population comparison). Parental psychosis, paternal age and offspring language were associated with offspring risk. The findings suggest that paternal exposure to lead is not a risk factor for schizophrenia in offspring. However, the majority of exposed fathers had low-level exposure, and we cannot exclude the possibility of an effect for higher exposures to lead.
Centre of Expertise for Health and Work Ability, Finnish Institute of Occupational Health, P.O.BOX 40, FI-00251 Helsinki, Finland. Electronic address: markku.sallmen@ttl.fi.
Markku
M
Sallmén
Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, P.O.BOX 30, FI-00271 Helsinki, Finland; Tampere School of Public Health, University of Tampere, FI-33014 Tampere, Finland. Electronic address: jaana.suvisaari@thl.fi.
Jaana
J
Suvisaari
Centre of Expertise for Health and Work Ability, Finnish Institute of Occupational Health, P.O.BOX 40, FI-00251 Helsinki, Finland. Electronic address: marja-liisa.lindbohm@ttl.fi.
Marja-Liisa
ML
Lindbohm
NYU School of Medicine, Department of Psychiatry, InSPIRES, 1 Park Avenue, 8th Floor, # 222, New York, NY 10016, USA. Electronic address: dolores.malaspona@nuymc.org.
Dolores
D
Malaspina
NYU School of Medicine, Department of Psychiatry, InSPIRES, 1 Park Avenue, 8th Floor, # 222, New York, NY 10016, USA. Electronic address: mark.opler@prophase.com.
Mark G
MG
Opler
D000293:Adolescent; D000328:Adult; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D007802:Language; D007854:Lead / Q000097:blood* / Q000633:toxicity; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016273:Occupational Exposure; D010331:Paternal Age; D018812:Paternal Exposure; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology*; D055815:Young Adult
D007854:Lead
Blood lead; Paternal exposures; Register-based study; Schizophrenia spectrum disorders