The pharmaceuticals industry is today one of the leading industries. With the growth of the pharma market, environmental concerns are on the rise—pertaining to not just production, but also consumer waste and disposal.
During the manufacture, use and disposal of pharmaceuticals, active pharmaceutical ingredients (APIs) as well as other chemical ingredients are released into the environment. Several APIs are known to persist and accumulate in the environment.
Pharmaceuticals have been found in surface waters, such as lakes and rivers, as well as in soil, groundwater, and drinking water all over the world.
Effect of Pharmaceuticals on the Environment
Improperly disposed medications, which are considered a toxic waste, once they find their way into streams and drinking water, have an adverse impact on humans, wildlife, and agriculture.
The adverse effects of the presence of drugs in water bodies have been observed and noted. For instance, the diabetes drug Metformin could be having a feminising effect on male fish, and may decrease their ability to reproduce. According to a report in Nature, many of Europe’s rivers are home to male fish that have become ‘intersex’ and so display female sexual characteristics, including female reproductive anatomy, owing to pollution by pharmaceuticals. Toxicologists blame this feminisation on endocrine-disrupting chemicals—particularly the active ingredient in the contraceptive pill, ethinylestradiol (EE).
It was found that, as a result of manufacturing facilities releasing active ingredients of drugs into nearby waterways, localised hotspots of pharmaceutical pollution are created. For example, in Hyderabad, two years after high concentrations of antibiotics were detected in water bodies downstream of several drug manufacturing facilities, high levels of known antibiotic resistance genes were found in the bacteria there.
In most cases, however, as the concentrations of pharmaceuticals found in the environment are much lower than the therapeutic dose, it can be difficult to determine what, if any, effect the drugs have on the ecosystem. The affected organisms, such as algae or sea lice, are seldom in the public eye, or the effects are mild enough to go unnoticed if researchers are not specifically looking for them. Generally, the absence of the required degree of surveillance is absent until there is a population crash in a larger animal. Such a population crash occurred between 1996 and 2007, when millions of vultures in India died by exposure to the anti-inflammatory drug diclofenac, driving the birds to near-extinction.
Other ecotoxicological effects of drugs in the environment have been found—the veterinary anti-parasite drug ivermectin, for example, has been found to reduce the number and variety of insects in cow dung, which can delay dung degradation and potentially reduce the amount of food available to birds and bats.
Laboratory studies have found that anti-depressants can alter the spawning behaviour of clams, disrupt movement in snails, cause altered aggressive behaviour in crayfish, and affect learning in cuttlefish and that the anti-inflammatory drug ibuprofen can affect reproduction in fish, such as the delayed hatching of eggs.
The presence of antibiotics in the environment also contributes to the problem of antimicrobial resistance (AMR), which has emerged as a major threat to human health.
The problem is likely to get worse as the world’s population ages. Moreover, there are no detection methods for all of the thousands of pharmaceuticals in use around the world, and the analytical methods are not standardised internationally, so detection limits may vary. Also, some drugs are worse than others because of their potential to affect the wildlife or people.
Proper Procedure for Disposal Ignored
Despite the high concerns on the threats posed by pharmaceuticals, their release into the environment is almost unregulated.
Pharmacists are expected to comply with rules for disposal of medications no longer wanted. Currently, high temperature incineration at suitably permitted facilities is the safest disposal method for toxic left-over medications. This is the method the pharmaceutical industry is expected to use to dispose of their unwanted medicines. However, even hospitals dispose of pharmaceuticals, except chemotherapy agents, by simply throwing them down the drain or sending them to the landfill, and people generally throw excess medicines in the garbage.
If household garbage goes to an incinerator, medication gets disposed of safely. If household garbage goes to a landfill, it is not as good a method of disposal as taking them to designated pick-up sites, but is still preferable to flushing them into the sewage system. A large percentage of the active ingredients in drugs consumed by people does not metabolise and ends up in human waste. Excess drugs in the bloodstream leave the body through urine and faecal matter, and the excreted chemicals flow with the sewage out of our homes to the streams and lakes. The metabolites of many drugs can also remain active in the environment after being excreted. The tendency to flush leftover medicines down the toilet or wash them off in the sink results in drugs ending up in sewage treatment plants, which were generally not designed to remove such pollutants from wastewater.
How to Tackle the Problem
Emission of pharmaceuticals into the environment needs to be regulated. Adequate information and transparency on the environmental impacts of pharmaceuticals should be ensured. Adequate and reliable evaluation of environmental risks of pharmaceuticals should be made and publicised. Actions to counteract adverse effects throughout the lifecycle of pharmaceuticals from design and production through use to disposal must be put in place. Environmental releases of pharmaceuticals should be prevented throughout their lifecycle and, when prevention is not feasible, emissions of pharmaceuticals to the environment should be controlled. Correct disposal of unwanted medicines and improving the treatment of sewage are necessary.
Source control is necessary, that is, reducing the quantity of pharmaceuticals that enter sewage systems. But that will be expensive. Some feel the drug industry should bear a large portion of the cost in a ‘polluter pays’ scheme. The pharmaceutical companies should take more responsibility for their products over their life cycle, they say.
It is necessary to educate people about the possible environmental effects of what they stock in their medicine cabinet, and encourage them to return unused drugs to the pharmacy for proper disposal.
In the United States, many environmental groups, health organisations, police, drugstores, and drug manufacturers participate in drug take-back programmes.
In Sweden, drugs are graded on their environmental effects, and doctors are required to prescribe a less damaging drug where the option exists.
A more long-term solution might lie in the concept of ‘benign by design’, in which drugs are designed from the start to be less harmful to the environment. Many drugs include molecules that are not found in biology—such as halogen groups—that make them more persistent in the body and the environment. These need to be avoided. Scientists have to be involved much earlier in the drug discovery process to advise on how to balance efficacy with environmental concerns. The increasing importance of biologic drugs, which break down more readily, will also help.
© Spectrum Books Pvt. Ltd.