The impact of pharmaceutical residues in water is largely unknown and though the evidence base is slowly growing this is somewhat piecemeal.

It remains clear that the key problem is a deficiency in wastewater treatment that cannot remove excreted drugs present in urine, and overprescribing and overuse by man and in animal husbandry, as noted previously here on the Clinical Waste Discussion Forum.

Though there are strict controls in the UK, including those purported falsely to prevent disaster from the trace residues present in most clinical wastes, India lags far behind. But India is now dealing actively with a new twist to this problem. In India, the cow is sacred and no matter how ill no cow should be destroyed. So, to keep them relatively pain-free it has become common to administer the anti-inflammatory diclofenac. That may help, but excreted in urine it enters the water systems and is causing widespread problems of contamination. But in an additional twist, the already endangered Indian vulture is suffering too.

Diclofenac concentrations in the tissues of fallen cattle are apparently so high that when vultures feed upon them the concentrations are sufficiently high to kill the birds. Numbers are plummeting, and after some pressure India has banned the use of diclofenac (Votarol) on cows but an illicit trade has now begun since the permitted alternatives are more expensive and less effective.