And The World's Worst Air Award For 2016 Goes To . . . Onitsha, Nigeria!!
Approaching Okpoko market through thick smog on the back of an okada (motorcycle taxi), the natural reaction is to cover your nose to protect yourself from the dust storm – but the effort is futile. When a lorry zooms past, kicking up yet another red cloud of dirt, a trader turns the head of a sleeping toddler away from the road, a protective act that is as poignant as it is pointless.
This is a typical day in the southern Nigerian port city of Onitsha – which last year gained notoriety when it was ranked the worst city in the world for the staggering levels of PM10 particulate matter in its air. Onitsha’s mean annual concentration was recorded at 594 micrograms per cubic metre by the World Health Organization – massively exceeding the WHO’s annual guideline limit for PM10s of 20μg/m3.
PM10 refers to coarse dust particles between 10 and 2.5 micrometres in diameter, while PM2.5s are even finer and more dangerous when inhaled, settling deep in a person’s lungs. Sources of both include dust storms, gases emitted by vehicles, all types of combustion, and industrial activities such as cement manufacturing, construction, mining and smelting. Onitsha scores highly on most of the above – as do other rapidly growing Nigerian cities such as Kaduna, Aba and Umuahia, all of which also featured in the WHO’s 20 worst offenders for PM10s.
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The air quality proves just as bad at Ochanja market, with PM10s registered at 586 micrograms and PM2.5s at 266. Yet in these highly polluted areas, few people show any sign of trying to protect themselves from the threat. There are only a few air masks in sight. A good number of aluminium and copper recyclers are not wearing masks, even while smelting metal scraps. Worse still, most smelting activities are done in the open, releasing monstrous clouds of smoke into the core of the city.
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https://www.theguardian.com/cities/2017/feb/13/polluted-onitsha-nigeria-perpetual-dust-city-world-worst-air