Knowledge of MercuryToxicity and Human Exposure: A PLS-SEM Mediation Analysis of Water, Vegetables, and Fish Consumption in Kitwe Mining Area, Zambia

Abstract

Mercury (Hg) in all forms (Hg0, Hg2++, Hg++; CH3Hg+) is a neurotoxicant that causes Minamata disease, which is characterised by permanent brain damage, central nervous system disorder and kidney damage. This study aimed to establish the role of Hg awareness in reducing exposure through the consumption of contaminated water, fish, and vegetables. A cross-sectional descriptive survey was conducted on 306 participants who consisted of fish and vegetable farmers and their households in the Kitwe mining area. Statistical Package for Social Sciences (SPSS) was used for the descriptives, and the partial least squares structural equation modelling was also used for the analysis. The results showed that the level of knowledge of Hg toxicity of the participants had a positive impact on the attitudes toward Hg exposure through the consumption of vegetables (Original sample (O) = 0.705, t = 32.568, P < 0.05). The participants who had environmental knowledge about the effects of effluents from the mining and industrial processes on the environment were more health-conscious about the source of vegetables for consumption. However, Hg consumption through vegetables did not meaningfully influence overall Hg exposure (Original sample (O) = 0.019, t = 0.118, P = 0.906). The knowledge of Hg toxicity has a positive effect on the attitudes towards Hg exposure through the consumption of fish (Original sample (O) = 0.763, t = 37.977, P < 0.05). The level of knowledge of the participants had a positive impact on their attitudes toward Hg exposure through the consumption of fish. The result in the current study also shows that participants who were knowledgeable about Hg exposure through the consumption of fish were more likely to be mindful of the source of fish and vegetables they were consuming. In conclusion, overall, knowledge of Hg toxicity significantly shaped perceived exposure pathways, but the low explained variance in total Hg exposure (R² = 0.042) suggests that additional factors, particularly occupational exposure and socioeconomic conditions, play a substantial role. The findings highlight the need for integrated interventions that combine awareness, behavioural change strategies, and mitigation of external exposure sources to effectively reduce Hg-related health risks.