Microplastics the ‘euthanasia’ of biodiversity
A Kosawo Primary School pupil drinks water from a tap at the school during break on October 28, 2016. A global scientific study has revealed that 83 per cent of water flowing from taps around the world is contaminated with microplastics.
The UN agency Unep’s analysis of water and sediments worldwide shows that microplastics are ubiquitous in freshwater, marine ecosystems, soils and even in the atmosphere.
In 2014, the United States’ National Oceanic and Atmospheric Administration (NOAA) estimated an intrusion of 51 trillion pieces of plastics in the ocean (outnumbering the stars in the Milky Way by 500 times!) A recent study shows microplastics ‘hotspots’ could contain as much as 1.9 million pieces per square metre.
Worst of all, traces of microplastics are present in edible fruits, vegetables and drinking water.
The wear and tear of macroplastics on land and in water bodies causes the plastic materials to be shredded into tiny particles as tiny as less than five millimetres long (0.2 inches).
They find their way into the water bodies through natural weathering processes that further renders them to tiny pieces. They enter the water bodies through pathways such as run-off from contaminated lands or from municipal wastewater and through atmospheric deposition.
A recent OrbMedia study reveals that both tap and bottled water contain 4.34 plastic particles per litre. That corroborates the fact that our lives are plasticised, even as a World Wide Fund for Nature 2019 report indicates that the average person consumes 1,769 tiny microplastic particles every week.
Biomagnification (accumulation of these microplastics and the inherent chemicals in the tissues of animals) up the food chain would mean that humans at the top of the food chain would accumulate more of the toxins. The microplastics contain chemicals such as polycyclic aromatic hydrocarbons (PAHs) that are carcinogenic (prone to cause cancer). Their build-up in the bloodstream causes hardening of arteries (atherosclerosis), leading to blockages, hence heart attack.
Keeping the microplastic pollution in check could prove cryptic as they hail from a myriad sources, thereby plunging the control of their spread into indeterminate state. A combination of aquatic efforts and land-based approaches is, thus, needed to at least address the runaway effects.
It is incumbent on us to take care of the macroplastics on land even as research indicates that up to 80 per cent of microplastics in water bodies originate from land. This is a great threat to the marine and aquatic ecosystem and subsequently detrimental to human life, bearing in mind the energy or food transfer from the lower to upper trophic levels.
The 2017 ban of the single-use bags is not fully successful. Indeed, the polythene bags are still a nuisance, especially in the informal parts of major towns. The illegal manufactures or the illegal entry portals should be dealt with to arrest the escalating accumulation of microplastics on land, even as plastic bottles are phased out.
Simon Bodo, Nairobi
