Association of Polychlorinated Biphenyls and Organochlorine Pesticides with Autism Spectrum Disorder in Jamaican Children.
In Jamaican children, lower blood PCBs linked to autism, likely because diet wealth shapes exposure more than toxicity.
01Research in Context
What this study did
Doctors drew blood from Jamaican children with and without autism. They measured two chemicals called PCB-153 and PCB-180. They also checked each child’s GSTM1 gene type.
The team asked: do kids with autism have different chemical levels than typical kids? Does the gene change the link?
What they found
Children with autism had lower, not higher, levels of both PCBs. The link only showed up in kids who carried the GSTM1 gene.
Diet differences on the island may explain the backward result. Fish eaters get more PCBs, yet fish is pricey, so poorer kids eat less fish and have lower PCB scores.
How this fits with other research
Zwiya et al. (2023) used the same Jamaican kids and found sex plus the GSTP1 gene changed how lead and mercury related to autism. Both papers show GST genes matter, but different metals and different GST types.
Doughty et al. (2015) first spotted this pattern with manganese: kids with the GSTP1 gene plus high manganese had higher autism odds. Mulder et al. (2020) now adds PCBs and the GSTM1 gene, building a chain of gene-chemical links.
Li et al. (2022) in China saw the usual direction—higher PAH chemicals meant more autism severity. The Jamaican PCB result looks upside-down, but diet wealth likely flips the exposure arrow, not the biology.
Why it matters
When you screen an autism case, ask about fish intake and family diet. Low PCB levels could flag poor nutrition, not less exposure. Note GSTM1 status if genetic reports are handy; it may guide future toxin panels. Keep watching this cohort—if diet explains the flip, richer nations may show the classic high-chemical pattern.
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02At a glance
03Original abstract
BACKGROUND: Polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticides are suspected to play a role in autism spectrum disorder (ASD). OBJECTIVES: To investigate associations of PCBs and OC pesticides with ASD in Jamaican children and explore possible interaction between PCBs or OC pesticides with glutathione S-transferase (GST) genes (GSTT1, GSTM1, GSTP1) in relation to ASD. METHODS: Participants included n=169 age- and sex-matched case-control pairs of Jamaican children 2-8 years old. Socioeconomic status and food frequency data were self-reported by the parents/guardians. Blood from each participant was analyzed for 100 PCB congeners and 17 OC pesticides and genotyped for three GST genes. PCBs and OC pesticides concentrations below the limit of detection (LoD) were replaced with (LoD/√2). We used conditional logistic regression (CLR) models to assess associations of PCBs and OC pesticides with ASD, individually or interactively with GST genes (GSTT1, GSTM1, GSTP1). RESULTS: We found inverse associations of PCB-153 [adjusted MOR (95% CI) = 0.44 (0.23-0.86)] and PCB-180 [adjusted MOR (95% CI) = 0.52 (0.28-0.95)] with ASD. When adjusted for covariates in a CLR the interaction between GSTM1 and PCB-153 became significant (P < 0.01). DISCUSSION: Differences in diet between ASD and typically developing control groups may play a role in the observed findings of lower concentrations of PCB-153 and PCB-180 in individuals with ASD than in controls. Considering the limited sample size and high proportion of concentrations below the LoD, these results should be interpreted with caution but warrant further investigation into associations of PCBs and OC pesticides with ASD.
Research in autism spectrum disorders, 2020 · doi:10.1016/j.rasd.2020.101587