Many Doors of Drug Disposal
The unsupervised disposal of pharmaceuticals is giving birth to a host of new challenges – contamination of water sources, poisoning of agricultural produce and outbreak of infection among civilians
The habit of disposing leftover medicines with household garbage has allowed the transfusion of outdated drugs with potable groundwater. Subsequently, if the practice is not halted, the residents of Delhi-NCR could soon develop a strong resistance against antibiotics upon unsupervised consumption of drugs in milk, vegetables or other agricultural produce. Moreover, the careless dumping of medicines can also witness the development of a superuser that most antibiotics cannot eliminate from the human body, says All India Institute of Medical Science in its research findings.
Ever since the first report on the development of superbugs, efforts have been taken to streamline the indiscriminate use of antibiotics among the general population of the country. Meanwhile, the utilisation of bioactive compounds in the agricultural and veterinary sector, and to fulfil other human requirements is having a profound impact on the ecological system. The AIIMS research further revealed that keeping a check on the exposure of leftover medicines to the environment is of utmost importance.
However, in 2015, researchers from the ocular pharmacology division of AIIMS began researching on pharmaceutical contamination in the Yamuna, in the quest of explaining the emergence of superbugs. The team, headed by Dr T Velpandian, analysed water samples from seven different points of the stagnant river – including its entry and exit points in the city, 35 borewells in Delhi-NCR and water percolating through waste at the Ghazipur landfill. The study revealed that the concentration of dissolved drugs increased manifold along the Yamuna's course.
Further, the study also states that concentrations of fluconazole (antifungal), ofloxacin (antibiotic) and ibuprofen (painkiller) were less than 0.05 micrograms per litre at its entry near Wazirabad in north Delhi. A microgram is a millionth of a gram, so 20 million litres of river water contained 1g or less of these drugs. Presence of painkiller diclofenac was almost the double – 0.1 micrograms per litre.
Drug concentration is alarmingly high in the groundwater near Ghazipur landfill. The unused drugs that you dispose without thought could be coming back to you in milk, vegetables and other agricultural produce, the study added. At the Yamuna's exit near Okhla barrage, the concentrations of fluconazole, ofloxacin and ibuprofen increased by 80, 96 and 50 times, respectively, whereas diclofenac increased by 121 times. The team's findings have been published in the latest edition of the journal Environmental Science and Pollution Research.
To find the sources of pollution, the researchers tested groundwater samples along with the water percolating from the Ghazipur landfill. "We found alarming drug concentrations across the area adjacent to the Ghazipur landfill. This means that a lot of unused drugs, expired or not, which are thrown into dustbins, end up at the landfill, percolate into the local drains and finally land up in the Yamuna," Dr Velpandian said. Delhi and other densely populated areas need a strict policy for separating and destroying bioactive compounds so that they do not accumulate in the environment.
Continuous monitoring of bioactive compounds in water resources by the responsible organisations and creating a sense of awareness on the disposal of unused or expired medicines is a matter of urgency. L Moksha, a co-author of the study, said that in some developed countries, unused drugs have to be returned to pharmacies and they are incinerated. People throw away expired medicines thinking they are useless but they are still active though their potency may have decreased.
Due to the excessive decomposition of the unused medicines at the three landfill sites of the Delhi, changes were observed in the pH scale. The profound impact of the organic/inorganic contents on the solubility and sedimentation, including APCs at the riverbed, clearly shows the fivefold difference in the osmolarity of the water samples. Studies around areas having a predominant number of industries – Sonipat, Loni, Sahibabad and Shalimar Garden – revealed that the industrial effluents flow into the Yamuna through open drains.
The decreased TDS/osmolarity ratio to the extent of more than 90 per cent indicates the possibility of contamination with organic compounds including various industrial solvents. The level of antimicrobial agents in the river Yamuna has been rising in Delhi. On the banks of the river at Mathura, 200 km away from New Delhi, the presence of pathogenic E Coli has been observed across 40 per cent of the samples used for studies by various agencies. Anita Sukmawati's study on biodegradable micro-particles reports the existence of significant antimicrobial drug resistance in the E Coli. A recent multicentric antimicrobial resistance study on pathogens causing sepsis in neonates in Delhi has also revealed the presence of an alarming degree of antimicrobial resistance, including fluoroquinolones (DeNIS: Investigators of the Delhi Neonatal Infection Study collaboration 2016).
Surprisingly, the same story unfolds in Mumbai, where sewage is drained into the sea. The existence of a high concentration of pharmaceutical drugs that are potentially disastrous for aquatic life has also been observed by scholars of the Indian Institute of Technology-Bombay (IITB). The untreated pharmaceuticals are first discharged into the sewers and then into wastewater treatment plants (WWTP).
"When we consume any medicine, 30 per cent is absorbed by the body and about 70 per cent gets excreted which further goes into the sewerage treatment plants. But, these treatment plants are not designed to treat medicines," said a doctoral student from the Centre for Environmental Science and Engineering, IITB.
"Elevated levels of pharmaceuticals entering the creek before ultimately reaching the sea can affect aquatic life and humans in the long run," few doctoral students said. To further draw understandings, a four-member team from Mumbai selected 12 commonly-used pharmaceuticals from an initial list of 72 for seasonal monitoring at two WWTPs in the city. Results showed that the average load of pharmaceuticals on reaching the two treatment plants was 537 microgram per litre (ug/l) and 353 ug/l. Upon drawing a parallel analysis, pharmaceutical concentrations in two WWTPs in the US was found to be 50 per cent less than Mumbai's.
It is high time that we as individuals ponder over the effects of disposing medicines carelessly. In general, expired pharmaceuticals do not represent a serious threat to public health or to the environment but improper disposal may be hazardous and can lead to the contamination of water supplies or local sources used by communities in the vicinity along with the flora and fauna. In the absence of suitable disposal sites and qualified personnel to supervise the disposal, the threat of unwanted pharmaceuticals can be contained provided they are securely stored in dry conditions.