Danger lurks in Nairobi River and it is not the first time the once majestic resource is finding itself in trouble.
A new research now shows Nairobi River has nearly 1,000 times more drugs from active pharmaceutical ingredients than those in the developed world.
Samples from Nairobi and part of Athi rivers tested positive for elevated levels of caffeine (stimulant), carbamazepine (antiepileptic), amitriptyline (antidepressant) and fluconazole (antifungal).
There were also high levels of trimethoprim, sulfamethoxazole ciprofloxacin, which are antibiotics. These ingredients were found up to 75km downstream from Nairobi.
Scientists from universities of Plymouth in the UK, New York in America and Jomo Kenyatta sought to find out where the chemicals came from, the level of occurrence and the risk they posed to human health. They collected samples in 27 locations along the river catchment and analysed them at University of York. They found 55 pharmaceutical ingredients and 45 compounds.
The study, published in the Journal Science of The Total Environment, identified the primary sources of the chemicals as “direct discharge of untreated domestic wastewater from slums, the industrial area of Nairobi where drug formulation is known to occur, a major landfill site and veterinary medicines from upstream agricultural use”.
Dr Sean Comber from University of Plymouth, and an author of the paper, said these chemicals posed the risk of antimicrobial resistance since the river’s water was in many homes for domestic use. Antimicrobial resistance is the failure of drugs to cure diseases. There are many factors that cause resistance including being exposed to subtle doses of the drugs.
On the university’s website, Dr Comber, an associate professor in Environmental Chemistry, made note of Nairobi’s rapid population, where development is unchecked and the development of an urban area that has outpaced the creation of sanitation infrastructure.
Every time it rains, it is common for sewers to burst and flood the city and houses in Nairobi as the sewerage system is overworked.
He said the sewerage system was built to cater for a population of one million people. However, the city has 4.4 million people, according to the 2019 census results.
A 2018 Health ministry analysis of sanitation in Nairobi, ranked the city position 42 out of 47 counties: about one per cent still defecate in the open, and another 13 per cent have unimproved sanitation sites. The report also reported that Sh1.7 billion was spent annually to treat diseases due to poor sanitation.
Dr Comber wrote: “Industrial areas, informal settlements and open landfill sites all polluting its river system. Extensive use of pit latrines within informal settlements means that untreated sewage either enters the environment directly or leaches through groundwater.”
The researcher also said the sewage “exhauster” lorries often pump waste out of latrines and dump it into the river.
This damage to health, ironically, is linked to the clamour to safeguard health. Many developing countries are developing medication to meet the rising need for antimicrobials such as antibiotics, but — as this study shows — the development of medication is not accompanied by environmental sustainability. “Access to healthcare and environmental protection are two of our sustainability priorities and this research is part of a wider programme of work to help ensure that access to medicines does not compromise environmental protection,” he said.
This study comes two months after a Nation study revealed dangerous levels of heavy metal in a river from Ondiri wetland in Kikuyu, Kiambu all the way to the Coast.
By the time of going to press, the National Environment Management Authority had not responded to our queries on the report.