A survey was conducted on pollution of 525 ponds across some cities. It was found that 230 ponds are polluted by fertilisers (F)(F), 245 ponds are polluted by pesticides (P)(P) and 257 ponds are polluted by pharmaceutical products (Ph)(Ph). 100 ponds are polluted by fertilisers and pesticides, 82 ponds are polluted by fertilisers and pharmaceutical products, 77 ponds are polluted by pesticides and pharmaceutical products.​