Human Exposure Assessment of Mixed Metal/Loids at and Near Mega-Scale Open Beaching Shipwrecking Activities in Bangladesh

Abstract

Pollution from shipwrecking is growing into a major occupational and environmental health concern worldwide, especially in the lower-middle-income countries where workers and residents may be exposed to potentially high levels of dispersed metal/loids due to decades of improper waste disposal. This study is the first to report the urinary biomarkers estimating the exposure of metal/loids and associated significant determinants in residents working and/or living at and near a major open beaching shipwrecking yard in Bangladesh. The concentrations of 17 elements were measured in urine and drinking water samples (125 each) using a validated ICP-MS method. Hydration variations of urine were best adjusted by specific gravity. Significantly higher (p < 0.001) urinary metal/loids load including cadmium and molybdenum in the occupational (70–80% of shipwrecking workers) and environmental exposure groups (72–75% of the local population) compared to the control site and international reference values suggest a significant health threat. Gender and age effects on the variation of urinary metal/loid concentrations were insignificant. However, fertilizer/pesticide users had higher nickel concentrations. Quantile regression analyses suggested the impacted locations with shipwrecking activities are significant predictors of exposure. The participants from the shipwrecking yards and the adjoining east, north, and south sites experienced significant exposure to metal/loids, which may be largely governed by wind-associated dispersion of contaminants. Water metal/loid concentrations were lower than the guideline values set by WHO and Bangladesh except for manganese in 63% of water samples. However, the elevated urinary concentrations of cadmium and thallium were significantly correlated to their concentration in water. This biomonitoring approach could be used as a background study to facilitate a more detailed exposure and health risk assessment to inform a management strategy for residents exposed to contaminated environmental matrices and dietary sources.