Groundwater contamination

 

Groundwater in Bangladesh, which is used as drinking water, is found to be contaminated with many heavy metals, including arsenic, lead, cadmium, chromium, copper, mercury, nickel, and uranium.^[3][4][5][6] Of these, arsenic has been determined to be the most significant health issue, with about 49% of the water being likely contaminated with concentrations above the WHO guidelines,^[6] affecting 35 to 77 million people within the country.^[7] Arsenic contamination of shallow groundwater is a naturally occurring problem that has been further made worse by the use of tube wells, which extract groundwater. Since the 1970s, the government started instituting the use of shallow tube wells to avoid the consumption of surface water, which is often contaminated with various bacteria.^[7] These tube wells, however, reached the arsenic-contaminated groundwater. This issue is more prevalent in inland areas^[3] and in rural areas, where 97% of the population uses tube wells.^[7] Health effects of consumption of arsenic-contaminated water include skin pigmentation changes and lesions, which could be a precursor to skin cancer. It can also cause lung and bladder consumption, as well as developmental effects, neurotoxicity, diabetes, pulmonary disease, and cardiovascular disease.^[8]

Lead contamination has been found to be high in areas around Dhaka. It has been postulated that this is due to the many industries in the area, including battery recycling facilities. The Department of Environment found more than 1200 industrial sites that caused significant pollution. Reasons for the additional metal contamination include mining and agricultural activity. The presence of lead in the water affects the environment, as well as human health. The presence of lead in the soil also led to a concentration of lead in the leaves of plants grown in the area.^[4]

In coastal areas, heavy metal contamination has also had an effect on marine life and the local ecology. This, in turn, affects the economic output of the region that relies partly on aquaculture. For instance, high levels of metals may affect the reproductive capabilities of the native ecology or contaminate the fish. If the fish have too high levels of metals, a fisher may not be able to sell them for consumption. If a consumer eats fish with high levels of metal contamination, he is at risk for health issues, such as cancer, kidney failure, or various metal poisoning. There is also a possibility that fish will move further away from these areas, to avoid the toxic areas, which would also affect the livelihood of the fishermen in the area.^[5]

There has been some effort by the government to provide deeper tube wells that are clearly marked as arsenic-free, as well as by various NGOs to provide filters to remove the heavy metal contaminants.^[9]