While industrial effluents and improper disposal of municipal waste are known causes of pollution, experts said another major source for groundwater contamination in the state are modern agricultural practices involving indiscriminate use of pesticides and fertilisers, resulting in build-up of agricultural toxins.
Andhra Pradesh, being one of the top three states in terms of pesticide use, pollution in groundwater caused by pesticides is fast becoming a cause of concern, said experts. Both the AP Pollution Control Board and the Groundwater Department warn that total pesticide levels have violated the desirable limits in many places in AP due to extensive use. Studies conducted in these places indicate almost 45 per cent chemical fertilisers, mostly in the form of nitrate, reach the groundwater, while almost 99 per cent of pesticide sprayed in an unscientific is released to the environment.
Officials said a significant percentage of chemical fertilisers find way to surface water and groundwater. After Tamil Nadu, AP uses maximum quantity of pesticides per hectare, said reports. “All these pesticides, herbicides and fungicides are non-biodegradable and highly poisonous for both humans and animals,” an APPCB official said. “A survey by the Centre for Science and Environment reported traces of heavy metals such as lead, cadmium, zinc and mercury in certain areas in AP. It was found many areas have fluoride-contaminated groundwater. Excessive use of prohibited pesticides and those used for mosquito control has also resulted in their accumulation,” he said.
The official said serious effects of these pesticides on the nervous system and even mutations in humans have been documented.