Alcohol Consumption, Blood Lead Levels and Aggressive Behaviour Among Adults Living Near Gold Mine Tailings in Gauteng, South Africa

Abstract

Abstract Lead (Pb) is a neurotoxin linked to aggression, while alcohol consumption, a major public health concern in South Africa, may also increase aggressive behaviour. This study examined associations between blood Pb levels and aggression in adults, and whether alcohol modified this relationship. A cross-sectional study was conducted among 199 adults, living at varying distances from gold mine tailings in Gauteng. Blood Pb were log-transformed and examined in relation to environmental exposures (proximity to roads and mine tailings), behavioural factors (smoking, soil ingestion), and soil Pb levels. Alcohol consumption was categorised as none, 1–4 drinks and ≥ 5 drinks per occasion (heavy episodic drinking). Aggression was measured using the 29-item Buss Perry Aggression Questionnaire (BPAQ), including anger, hostility, verbal, and physical aggression. Linear regression models were estimated for each aggression outcome, adjusting for age, alcohol use, blood Pb, and interactions between blood Pb and alcohol. Mean blood Pb was 2.4 ± 1.8 µg/dL (range 0.5–12.2 µg/dL), with 9.7% exceeding 5 µg/dL and 18.7% exceeding 3.5 µg/dL. Higher blood Pb was associated with soil ingestion (β = 0.29, p = 0.017), higher soil Pb (β = 0.08, p = 0.001), tobacco use (β = 0.20, p = 0.031) and household dust (β = 0.13, p = 0.043). Heavy episodic drinking was associated with higher total BPAQ scores (β = 19.7, p < 0.001) and all subscales. Blood Pb showed marginal associations with verbal and physical aggression, and alcohol did not modify the Pb-aggression relationship. In this population, heavy episodic drinking, rather than Pb exposure, was the main factor linked to increased aggression. Addressing harmful alcohol use may provide an opportunity to reduce a modifiable risk factor for aggression, while environmental Pb surveillance and remediation remain important in communities with ongoing Pb exposure.