Impact of safety interventions on behavioural changes and blood lead levels in Thai fishnet sinker workers

Lead poisoning is a public health concern, particularly for workers in high-risk industries like fishnet sinker manufacturing. This study evaluated the impact of safety interventions based on the Theory of Planned Behaviour (TPB) on safety behaviours and blood lead levels (BLLs) of fishnet sinker workers in Thailand.

A 6-month quasi-experimental study was conducted in two fishing-net sinker manufacturing villages in Nakhon Si Thammarat, southern Thailand, involving 60 workers assigned to an intervention group (n=30) or a control group (n=30). The intervention promoted protective behaviours such as hand washing, wearing masks, changing clothes after work, washing work clothes separately and cleaning work areas with a wet towel. Behavioural changes were assessed using TPB constructs, and a structural equation model was used to validate their relationships with behaviours. Lead surface contamination and BLLs were measured before and after the intervention.

After 6 months, the intervention group demonstrated significant improvements in self-reported safety behaviours. Median lead surface contamination remained unchanged (-1.9 µg/100 cm², p=0.918) and mean BLLs were maintained at preintervention levels (+0.6 µg/dL, p=0.431). In contrast, the control group showed no significant improvement in safety behaviours, experienced a notable increase in mean BLLs (+2.7 µg/dL, p=0.003) and had no significant change in lead surface contamination (+6.9 µg/100 cm², p=0.229).

The findings suggest that TPB-based interventions improve safety behaviours and prevent further increases in occupational lead exposure. These low-cost, resource-based strategies show potential for adaptation in similar high-risk industries, contributing to workplace safety and public health protection.