Is our air killing us?

At the risk of sounding alarmist, yes, it is. Our environment has a direct bearing on our health, and the air we breathe is deadly. Air pollution is a silent and invisible killer and is now recognised as the foremost environmental health problem in the world. According to the WHO, air pollution is responsible for up to 700,000 deaths throughout Africa every year. Unfortunately some cities in Nigeria have acquired the dubious distinction of being among the most heavily polluted in the world. Top of the global list is Onitsha, and somewhere there is my beloved city of Kaduna. It’s hard to believe that I live in this wonderful city, and breathe in some of the deadliest air in the world. At home, commuting to work, schools or markets, every day and all the time, we are inhaling poisonous air. Our babies, children and elderly are most at risk of a host of respiratory illnesses and even death. Our air is making all of us sick. We need to clean it up and we need to do this fast.

A bit of science is needed here to clarify what constitutes air pollution and why a city like Kaduna has such bad air. Pollutants in the air are typically a mixture of nitrogen dioxide, sulphur dioxide, carbon monoxide, tropospheric ozone, lead, particulate matter (PM) and some other toxic compounds such as benzene, dioxins and polycyclic aromatic hydrocarbons. But the most injurious to health is particulate matter (PM). This is the pollutant that has put our state capitals on the map. PM are very fine particle about 30 times smaller than human air. They are usually divided into PM10 and PM2.5. PM10 particles are 10-2.5 micrometres in diameter, while PM2.5s are even smaller and more dangerous when inhaled, settling deep in a person’s lungs. Last year, Onitsha was the highest in the world for PM10s, measuring 594 micrograms per cubic metre (ug/m3) against the recommended WHO limit of 20ug/m3. Kaduna was 423ug/ m3.

Emissions from our cars (most of which are old and burn fuel inefficiently), keke napeps, achabas, those ubiquitous yellow buses that have been plying Kaduna roads since my childhood, all mixed with PM from burning refuse, generator exhaust, wood burning, industrial activity and harmattan dust create a lethal mix. Exposure to PM whether short term or long term can bring about a host of respiratory and cardiovascular diseases, particularly pneumonia, bronchitis, influenza, asthma and whooping cough in children, and lung cancer, stroke and heart disease in adults.

Most of us have no choice but to use wood for cooking, ride keke napeps and achabas, drive inefficient old vehicles, burn domestic rubbish and use generators. Rolling up our car windows and turning on the air conditioning provide no protection and believe it or not, only make it worse. Studies have shown the air inside cars is up to 20 times worse than that outside, as fans suck in the toxic air and concentrate them inside. Masks offer no defence against PMs either; they go right through them or seep in from the sides. We can’t stop breathing, so we have to clean up our air.

It’s very easy to point out a problem; doing something about it is much harder. As individuals we can do our bit - don’t burn rubbish, keep babies and young children away from smoke and noxious fumes especially on roads. But ultimately it is up to the government to tackle this problem. Air quality management is a long term process; but some cities such as Bangkok and Mexico City were able to achieve a considerable reduction in 10 years. They did this by overhauling their public transportation systems, mandating the use of catalytic converters in cars, reducing lead and sulphur in fuel and imposing strict emission standards for industry. Admittedly some of these things will be difficult to do in our cities now but we can start with a few. First, improve our solid waste management services and ban the burning of rubbish in that order, because you cannot do the second without the first. A city like Kaduna can also build a bus rapid transit system (BRT) such as the one in Lagos. This will reduce the number of pollution spewing vehicles on roads. Any reduction in vehicle emissions will make a difference.

The time to act is now as it is only going to get worse. One of the main drivers of increased air pollution is urbanisation, which in turn leads to increased energy use, more vehicles on the roads and more waste generation. Many cities in Nigeria are undergoing some of the most rapid urbanisation and population growth in the world and we can imagine that air quality will only decrease in proportion. The silver lining in the cloud (yes there is one) is that air quality measurements are even taking place. That’s a vital first step.

This invisible problem is easy to ignore, but we do so at or own (and our children’s) peril. Air quality management has to feature in our development agenda, but it needs proactive leadership. Will it happen any time soon? We all know that air pollution is only one in a long list of issues that need urgent attention. Our states have limited resources and a litany of other competing urgent problems, many of them also a matter of life and death, with the added (dis) advantage of being visible. So don’t hold your breath. Or on second thoughts, do.

Dr Saada Umaru Baba wrote this piece from Kaduna State University.