KUALA LUMPUR – The improper disposal of excess or unused medicines can over the long-term lead to environmental degradation, including the contamination of valuable water resources that can cause harm to aquatic life.
Whether indiscriminately dumped into garbage bins or flushed down the toilet, a good portion of the pharmaceutical waste will eventually end up in water bodies.
According to Dr Nurfaizah Abu Tahrim, a senior lecturer at Universiti Kebangsaan Malaysia’s Department of Chemical Sciences, even the excreted waste from medicines ingested by humans – as well as veterinary drugs – will eventually end up in sewage treatment ponds before being channelled into rivers.
Nurfaizah, who is also a researcher at UKM’s Centre for Water Research and Analysis, stressed that conventional treatment plants for sewage and raw water are not designed to treat medical waste.
“Hence, the residue of medicines will still be present in the treated sewage which is released into rivers… this can have an impact on aquatic life,” she told Bernama.
Nurfaizah said the presence of synthetic pharmaceutical substances in sewage was first reported during the 1970s by researchers in Kansas in the United States who detected chlorophenoxy isobutyrate and salicylic acid, which are metabolites of the drugs clofibrate and aspirin. (A drug metabolite is a by-product of the body breaking down or metabolising a drug into a different substance.)
Since then, researchers in western countries have detected the presence of various types of medications and metabolites in environmental samples.
Malaysian university researchers have not been left behind in studies concerning the presence of medical waste in aquatic samples.
“Studies on several water samples from rivers in this country revealed the presence of medicines such as acetaminophen, carbamazepine, gliclazide, metoprolol, nifedipine, prazosin and simvastatin albeit in very low concentrations,” said Nurfaizah.
Pharmaceutical waste that ends up in rivers can cause harm to aquatic life.
A comprehensive analysis methodology to detect the presence of pharmaceutical waste in the environment is still not available due to the diversity of the chemical and physical properties exhibited by the drugs concerned, she said.
“Apart from that, most of the analysis methodologies developed by researchers focus on a specific group of medicines,” she said, adding that among the pharmaceuticals detected in environmental samples are analgesics, antibiotics, hormonal contraceptives and drugs used to treat hypertension, epilepsy and diabetes.
Commenting on reports on the effects of hormones on aquatic species, Nurfaizah said chemical contamination is said to be the main cause of their hormonal changes as it affects their endocrine functions.
“This phenomenon is known as endocrine disruption and the World Health Organisation has identified it as a global issue,” she said.
Endocrine-disrupting chemicals (EDCs), or endocrine disruptors, are chemicals that can interfere with endocrine or hormonal systems and, often, steroid hormones are linked to this.
“International researchers have reported male fish developing female characteristics (due to EDCs),” she said, adding that not all pharmaceutical waste, however, is categorised as EDCs.
There is also no report linking the effects of pharmaceutical waste to human health, she added.
IMPROVE WASTE MANAGEMENT
Environmental activist and EcoKnights vice-president Amlir Ayat, meanwhile, said the government should formulate more practical procedures for the management of household waste which normally would include pharmaceutical waste.
He said household-generated pharmaceutical and clinic wastes such as unused medicines, medicine bottles and also face masks must be disposed of properly and not discarded indiscriminately as they may contain dangerous chemical substances and pathogens that are invisible to the naked eye.
“It will be good if the public has access to the authorities responsible for the systematic disposal of pharmaceutical and clinical wastes,” he said, adding that all medical centres should be registered with the Department of Environment to ensure their clinical wastes are disposed of safely.
Although the incidence of environmental pollution caused by pharmaceutical waste is small compared with contamination caused by chemical effluents, it should nevertheless be monitored continuously by the relevant authorities.
Society can do its part by complying with their medication regimen or returning their unused or excess medicines to the clinic or hospital concerned to facilitate safe disposal.