This article thoroughly investigates the severity of the prevailing environmental conditions and evaluates the resulting threats to food intake and public health in Bangladesh by establishing relationship among different contaminant transfer mechanisms to human. It describes the potential of certain contaminants to get bio-magnified through the food chain. A database was prepared on a number of contaminants in the study area that are responsible for rendering different foods vulnerable to produce long term or short-term health effects. Contaminants that have been identified in the food sources were categorized in a continuum based on their allowable daily intake. A protocol has been developed which will enable the assessment of the potential of a contaminant to bio-magnify through food chain to understand the contribution of a contaminant on different levels of food chain. The study also provides a detailed assessment of the public health risks associated with direct ingestion of adulterated foods and intake of contaminants through food chain or water intake. Their intake to human body was quantified, which provides an indication of the toxicity level of the contaminants and possible impact on human health. The traditional four steps of risk assessment technique have been employed for some model contaminants (including metals, organic contaminants, and food adulterants). Additionally, existing rules and regulations of Bangladesh were identified with possible limitations that can play significant role in controlling the food adulteration practices and concentration of contaminants in the environment and human body. Finally, a holistic approach to necessary interventions has been prescribed at policy, treatment and evaluation level to prevent the water pollution and food adulteration. Thus, a much-needed comprehensive framework is prescribed in this study to promote safety in food handling, preserve environment and improve health-based strategies in Bangladesh.

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This study investigated the magnitude of heavy metal contamination and determined the carcinogenic as well as non-carcinogenic risks associated with selected food consumption in Bangladesh. Commonly consumed varieties of rice, vegetables, and fish samples were analyzed to measure the concentrations of heavy metals such as cadmium, chromium, lead, arsenic, manganese, nickel, and zinc. These staple food items showed the greatest probabilities of heavy metal contamination in different phases of their production and marketing. Wide variations of metal concentrations were observed. Specifically, estimated daily intakes of arsenic and cadmium exceeded allowable daily intakes in all three food items. Toxicity scores of the metals were evaluated, and a comprehensive risk assessment was conducted to quantify the risks associated with the daily food consumption. Except for cadmium and lead in vegetables, all the contaminants present in each food item posed significant levels of carcinogenic risks up to 2.99 × 10 compared to the EPA recommended carcinogenic risk level of 1.0 × 10. Cadmium and arsenic intake due to rice consumption also posed unsafe levels of non-carcinogenic risks of 4.587 and 6.648, respectively, compared to the EPA recommended non-carcinogenic risk level of 1.0. Finally, a revised set of permissible limits was proposed for the heavy metals detected in the food items. Those permissible limits would ensure the risks associated with food consumption below the allowable carcinogenic and non-carcinogenic risk levels. Thus, this comprehensive approach would provide guidelines to formulate adequate control measures and regulatory limits of toxic metals in foods produced and marketed in Bangladesh.

Excessive concentrations of heavy metals impair ecosystems as some of those cause potential bioaccumulation in living beings. Fishes are the major inhabitants in water bodies which can be highly affected by these toxic pollutants. This study investigated the uptake trends of the metals copper and zinc from water in Anabas testudineous, a common fish species in Bangladesh. The accumulation of heavy metals was quantified in the species during time bound batch experiments with metal dosing. Metal uptake trend in fish muscles revealed that, uptake of Zn in fish occurred at an elevated level (~7-8 times) than that of Cu. With uptake of metals in fish muscles from water, Cu concentration in the water decreased concomitantly whereas the concentration of Zn did not change noticeably. Correlation analysis indicated significant changes in internal dynamics among water quality parameters between control and experimental tanks. Bio-concentration profile for the metals revealed very high levels for Zn (5-10 times) than those for Cu evidently due to higher amount of uptake of Zn. To summarize, dynamics of heavy metal metabolism in the fish species and their respective correlation with the water quality parameters may vary for different heavy metals and for different fish species as well.