Which of the ways of controlling bilharzia can result in pollution?

The way of controlling bilharzia that can result in pollution is applying chemicals to kill the snails. Bilharzia is a disease caused by a parasitic worm that spends part of its lifecycle in freshwater snails. One of the ways of controlling bilharzia is by applying chemicals to kill the snails and break their life cycle. However, the use of chemical molluscicides can result in pollution of the water bodies. When chemicals are applied in large quantities, they can accumulate in the water and become toxic to aquatic life, including fish and other aquatic organisms. In addition, some molluscicides contain persistent organic pollutants that can remain in the water for long periods and accumulate in the food chain, posing a risk to human health. Therefore, while applying chemicals to kill the snails may be an effective way of controlling bilharzia, it can also result in pollution of the water bodies, making it a potential environmental hazard.