Abstract:
Nowadays, majority of the people of Bangladesh are completely depending on groundwater for
household potable water use because surface water usage has previously led to some detrimental
health effects causing diarrhea, cholera etc. But, recently this groundwater source has also
become a dubious resource for the whole country as Arsenic and many other harmful metals
were discovered in it from national surveys. As a result of drinking this water, people are
severely suffering from skin and internal cancers as well as other non-cancer effects at many
places throughout the whole country. But it is unclear whether these effects are due to any
antagonistic or synergistic effect of toxic elements present in water. This study addresses
mixtures of chemicals in drinking water and potential interactions that might affect the joint noncancer
toxicity (Cardiovascular, Neurological, Hematological and Renal effects) of chemicals
present in potable drinking water in Bangladesh. Secondary data of Arsenic, Cadmium and
Manganese were garnered from potable drinking water sources of Bangladesh to evaluate the
individual as well as combined mixture toxicity of different chemicals. The present study has
utilized empirical methods with environmental data to analyze the additive hazard index and
interactive hazard index for illustrating different health effects. Results might help in scaling up
risk assessment studies for complex mixtures of different types of chemicals throughout the
entire country on a regional basis. The spatial variation of toxicity indices have also been
presented using Arc-GIS with three hazard index scores (additive, synergistic, and antagonistic)
for each mixture at upazila scale. Present analysis shows that, for cardiovascular, hematological
and neurological health effects, the individual effects of binary and ternary mixture of chemicals
are strongly interactive (synergistic or antagonistic) whereas for renal health effects binary
mixtures are mostly additive. More specifically, for neurological effects in almost every upazilas
of Bangladesh there is strong synergistic interaction of chemicals whereas for cardiovascular
effects in few places especially the northeastern zone and Meghna delta’s of Bangladesh, there is
strong likelihood of potential toxicity.
