Have you ever heard of fish engaged in family planning? In the nineties, a group of UK researchers chanced upon a phenomenon in fish that lived downstream from waste- water treatment plants. The males of this piscine population   became increasingly feminized, so much so, that they were busy producing eggs, in their testes. These fish were not meant to be on contraceptives, but thanks to human thoughtlessness, they were imbibing a regular dose. Such ‘cross- over’ samples are no longer strangers to the rivers and streams across the Americas and Europe. The reason-- estrogenic compounds in their habitat!

Drug Route

What is behind this strange phenomenon? The story begins with the multitude of drugs, masterminded in laboratories. They win approval through clinical trials, and are then mass- produced as purposeful remedies to save lives.

But the story does not end there, although the purpose is accomplished.  Expired or outdated drugs are disposed by flushing them down the toilets. Drugs are also excreted by consumers. They amalgamate with the environment through treated wastewater, agricultural run-offs and manure.  These drugs seep their way underground, wade their way into streams and ultimately enter the food chain.

Fishy Facts

Studies confirm that fish all over the world are being ‘slow poisoned’ with sips of estrogenic compounds besides anticonvulsants, such as carbamazepine, antidepressants, such as fluoxetine, and scores of other drugs that have been designed to brighten our lives. Carbamazepine affects the development of small insects that are savored by the fish, while fluoxetine slows development in fish and frogs.

What are the effects of these estrogenic compounds on fish? Studies on fathead minnows revealed that there was delayed sperm development in these fish and that, after a time span, the males were beginning to produce eggs. In effect they stopped reproducing. It came as no surprise, therefore that the population of these fish started to dwindle, to a point of near extinction, from the lake.

The low head count in the fathead minnows brought about a decrease in the number of trouts. The minnows are a major item on the trouts’ menu. When their food plummeted, the trouts too began to be fatally affected.

But this eco-story is not entirely sordid; it has a fitting finish to it. It must be noted that large quantities of estrogen are not required to bring about feminization in male fish. When the estrogen in their environment was controlled, the minnows population bounced back with renewed vigor. Hence it can be safely concluded that removing estrogen from their habitat can save the fish.

Vulture Woes

The effects of pharmaceutical pollution ramify across the environment and are not confined to the aquatic phase alone. Large- scale deaths of vultures in certain regions of Asia were traced to the rampant use of an anti-inflammatory drug, Diclofenac, among the animal stock.

Diclofenac is a drug of choice employed in the treatment of domestic cattle in India and Pakistan. When these animals die,they are feasted upon by birds of prey. It gradually came to light that the vultures that scavenged upon these carcasses suffered renal failure and visceral gout, as a result of diclofenac poisoning.