A RECENT study reports that the declining water quality caused by an unregulated use of pesticide and other forms of pollution is becoming a major public health concern. The study that the environmental science department of Jahangirnagar University conducted has detected a dangerous level of pollution in the surface water in 19 districts. Several emerging contaminants such as antibiotic residues, fluorescent whitening agents and microplastics have been found in water bodies. The pesticides, generally known as ‘forever chemicals’ because they are resistant to environmental degradation through chemical, biological or photolytic processes, are causing chemical contamination of water. An excess amount of microplastics found in the gut of 73 per cent of the freshwater fish surveyed confirms the contamination of the food cycle. Researchers are concerned that a regular intake of heavy metals through contaminated water could increase the incidence of cancer. There are other studies of the Bangladesh Agricultural University and the World Bank that have made similar observations about the presence of metal residues in the food chain that is adding to public health risks.

The study has also identified some other major reasons for the declining water quality. Some chemical pollutants found in water bodies include pesticides that have already been banned by the government. The poor regulation of the agrochemical industry, as many environmentalists suggest, is to blame for the situation. Moreover, the emerging pollutants are not part of the existing environmental monitoring programmes. Green activists have been vocal about the weak management and monitoring of industrial wastes. Many industrial outlets in the capital run without any effluent treatment plants and liquid effluents are discharged into rivers or water bodies. In a country with a high population growth rate, weak municipal waste management and poor sanitation system contribute to the declining water quality. The indiscriminate disposal of electronic wastes that contain mercury, silicon, tin, resin, cadmium, zinc and chromium also contaminates the soil and surface water. In the prevailing situation, people consume emerging pollutants, heavy metals and toxic particles of pesticide through drinking water and they are exposed to public health risks that include cancer and respiratory diseases.

The government must, therefore, take the issue of declining water quality, particularly the toxic contamination of surface water, seriously and immediately address the regulatory loopholes identified by the researchers. The environmental and food safety authorities must include the contamination of water from emerging pollutants in their routine monitoring programmes. The agrochemical industries must be strictly regulated to prevent the use of banned pesticide and the agriculture ministry should consider campaigns to inform farmers of the harmful effect of pesticide overuse. The government should also treat the research findings as a wake-up call and take steps to prevent the chemical pollution of water resources to avert any associated public health risks.