Which household activity can significantly contribute to water pollution?

Disposing of pharmaceuticals down the drain significantly contributes to water pollution because many medications are not removed during wastewater treatment processes. When these substances enter the aquatic environment, they can harm aquatic life and disrupt ecosystems. Pharmaceuticals can lead to the development of resistant bacteria and have been shown to affect the growth and reproduction of various species. This practice adds to the broader issue of emerging contaminants in water systems, which pose risks to both human health and animal life.

In contrast, using biodegradable cleaning products, installing water-saving fixtures, and composting kitchen waste are all environmentally friendly practices aimed at reducing pollution and conserving resources. These actions promote sustainability and help in minimizing negative impacts on water quality, unlike the disposal of pharmaceuticals, which actively contributes to pollution issues.