There is more evidence of the negative effects of human drugs on nature. For instance, there was a case where antidepressants, entering wastewater, changed the behavior of starlings. Consequently, the female birds became less attractive, and the males became aggressive and uninterested in finding mates.
Researchers also examined fish “hooked” on methamphetamine. Although this substance is used to treat certain disorders, it is widespread on the black market. According to the UN, it is the second most common drug in the world. Experiments showed that when methamphetamine entered the water, it caused dependence in fish. In a clean environment, the fish experienced “withdrawal syndrome,” stress, and, as a result, inability to move. In the wild, this dependence can result in fish preferring to live directly near the source of wastewater discharge, altering the life of entire ecosystems.
One research finds that minnows experience “anxiety” after exposure to caffeine, while another paper says perches lose their fear of predators due to antidepressants. A bear that died in the United States from a cocaine overdose has already become a symbol of man’s reckless attitude to nature.
One of the largest bird extinctions occurred in India, where the vulture population decreased by 99.9%. The culprit was an anti-inflammatory drug given to the local cattle. After the animals died, vultures fed on their carrion, indirectly consumed the medicine, and subsequently died of kidney failure. Without the vultures, carcasses were left to rot, spreading infection. Eventually wild dogs started to eat the meat instead of the birds, causing rabies to spread. As a result, using the drug for the Indian livestock led to more than 47,000 human deaths from rabies and $34 billion in economic damage.
There are a few ways narcotic and pharmaceutical substances can enter the environment. Factories dump drug residues during production. Some drugs end up in the sewer after being excreted from humans, and some are simply drained into a sink or a toilet. After all, this is how most of us would dispose of antibiotics leftovers, to then “sustainably” throw an empty plastic bottle into a recycling bin. Unused medicines also end up in landfills with other garbage.
A recent study clearly shows the scale of the problem. Scientists analysed the state of rivers in 1,052 locations across 104 countries. In 43% of cases, the level of at least one substance exceeded permissible safety standards. In the most polluted places, several different medicines were found in the water simultaneously. Importantly, global drug pollution is harmful not only to nature but also to humans, as these substances can enter groundwater used for drinking.
Scientists are sounding the alarm and calling for the “greeening” of the life cycle of medicines. Firstly, they propose training staff to more effectively dispense medicines, considering the environmental impact. Secondly, people need special campaigns informing them how to handle medicines to avoid pollution. Thirdly, manufacturers should not dump pharmaceutical waste into rivers and lakes and “improve” their formulas so that medicines more easily decompose in nature. A universal wastewater treatment system is also essential. At least half of all wastewaters (48%) is discharged into reservoirs untreated, and existing treatment plants are not designed to purify water of drugs.
