Africa has an air pollution problem – but lacks the data to tackle it

Another smoggy day in Abidjan. Image: Getty.

The World Health Organisation (WHO) recently launched BreatheLife, a campaign to make people more aware about the fact that air pollution – which it calls the invisible killer – is a major health and climate risk.

“Invisible” may refer to the lack of awareness that air pollution is a major health risk. In fact, air pollution levels exceeding the WHO air quality guidelines are often very visible, particularly in developing countries. This is especially true for billions of people living in close contact with air pollution sources. Those who, for example, cook on inefficient stoves with fuels such as coal. Or live in an industrial area.

The WHO has air quality programmes for most of the world’s regions. These review the effects of air pollution on health and help countries develop sustainable air quality policies. But none exists for sub-Saharan Africa. It is not clear why. A possible explanation may be that environmental health risk factors are overshadowed by other risks like malnutrition, HIV, tuberculosis and malaria.

Despite this, we do know something about the continent’s air pollution levels. In the first major attempt to estimate the health and economic costs of air pollution in Africa, an Organisation for Economic Co-operation and Development report found that air pollution in Africa already causes more premature deaths than unsafe water or childhood malnutrition. It warned that this could develop into a health and climate crisis.

But how bad are air pollution levels in Africa? Which countries have the worst air pollution levels? What are the main sources and drivers of air pollution? Are the main sources and drivers of air pollution different from those on other continents?

The answers to these questions are severely hampered by a lack of data as well as poor regulation and laws in African countries. The only country on the continent that has ambient air quality standards enforced by air quality laws and regulations is South Africa. Other countries have either ambient air quality standards or air quality laws and regulations, or none at all.

What’s known

Air pollution is a complex mixture of many components.

The WHO’s air quality guidelines, as well as country-specific laws, have identified a few air pollutant components: particulate matter smaller than 2.5 micrometer (PM2.5) and 10 micrometer (PM10) in aerodynamic diameter, sulphur dioxide (SO2), ground-level ozone (O3), carbon monoxide (CO), benzene, lead and nitrogen dioxide (NO2).

The most dangerous are PM2.5 and ultrafine particles (UFP); the latter are smaller than 100 nanometer in aerodynamic diameter. PM2.5 and UFP penetrate deeper into the lung alveoli and may pass into the bloodstream. PM10 and PM2.5 are important indicators of long-term air quality and of health risks.

Based on data of ground measurements conducted in 2008-2015, Africa’s PM10 levels are not the highest in the world.

The database is the largest of its kind and covers over 3,000 human settlements – mostly cities – in 103 countries. The number one spot belongs to the Eastern Mediterranean region, followed by the South-East Asia region and then Africa. But the WHO acknowledges numerous limitations to the data sources. Fewer sites globally measure PM2.5, hence the focus is on PM10.

The PM2.5 data based on the WHO air quality model show that the number one spot again belongs to the Eastern Mediterranean region, followed by the South-East Asia region and then Africa. Given the lack of PM2.5 ground measurements in Africa, the PM2.5 data derived from the WHO air quality model for Africa should be viewed with caution.

Where is the air worse in Africa?

It is hard to say what the real picture is. The modelled PM2.5 data supplements the data from ground monitoring networks, especially in regions with no or very little monitoring, as is the case in Africa.

The PM10 data, based on ground measurements conducted between 2008 and 2015, show that all African countries with PM10 data exceeded the WHO annual guideline of 20 microgram/cubic meter (µg/m³).

Onitsha in Nigeria had the highest yearly PM10 level of 594 µg/m³ globally, nearly 30 times higher than the WHO annual guideline. But the quality of the data is questionable. The level for Onitsha is based on PM10 data collected only in 2009 and only at one site. The database also does not mention on how many days the 2009 yearly level is based as missing data can lead to a distorted yearly level. The lowest yearly PM10 level was recorded at Midlands in Mauritius (20 µg/m³). But this is based only on 2011 data collected again at only one site without mention of how many days in 2011 were measured.

It is also difficult to know exactly what the contribution of different sources of air pollution are in Africa.

The amount of air pollution in any given location is affected by a combination of local, regional and distant sources. It is also affected by the dispersion of pollutants, which in turn depends on numerous weather conditions such as wind direction, temperature and precipitation.

A recent review indicated that very few studies in Africa conducted source apportionment of PM2.5 and PM10. The review concluded that (based on the few studies) 17 per cent, 10 per cent, 34 per cent, 17 per cent and 22 per cent of PM2.5 levels in Africa are due to traffic, industry, domestic fuel burning, unspecified source of human origin and natural sources - such as dust and sea salt. For PM10 the corresponding source distribution is 34 per cent, 6 per cent, 21 per cent, 14 per cent and 25 per cent, but should be viewed with caution due to the few studies.

Based on the limited number of PM10 and PM2.5 source apportionment studies in Africa, these tentative conclusions can be drawn. Traffic is a major source of PM10 levels in Africa as in many other global regions. The other two major sources of PM10 in Africa are domestic fuel burning and natural sources. In other regions of the world, industry and the ambiguous “unspecified source of human origin” contribute more.

Domestic fuel burning is the major source of PM2.5 in Africa, followed by traffic and natural sources such as dust. In other regions of the world, traffic, industry and the ambiguous “unspecified source of human origin” contribute more to PM2.5 levels.

Air quality interventions

Regardless of the exact global source contributions, the main sources of air pollution should be tackled globally in management plans and interventions.

Obvious interventions include clean energy technology such as solar power, to minimise domestic fuel burning and emissions from coal-fired power plants. Other initiatives include clean public transport, bicycle lanes to cut traffic emissions, recycling and controls on industrial emissions.

Air pollution does not stop at country or continental borders. It is a major risk factor for climate change. A disregard for air pollution levels in Africa may have a major impact on global climate change in the years to come.The Conversation

Janine Wichmann is associate professor at the University of Pretoria.

This article was originally published on The Conversation. Read the original article.


Who should decide how drones operate in cities?

A drone over Lille. Image: Getty.

Amazon recently filed a patent for a new technique involving parachutes and magnets to deliver parcels via drone safely to customers’ back gardens.

This came hot on the heels of 300 drones dancing over Lady Gaga’s Super Bowl performance only to be upstaged by a 1,000-drone light show in Guangzhou a few days later. Meanwhile, Japanese scientists have created drones that can pollinate flowers, offsetting global declining bee populations.

A decade or two from now it’s entirely plausible that we could see fleets of drones crisscrossing our cities. Some will be delivering medicine to housebound patients and vaccines to hospitals, while others will drop off lunches and contracts for harried city workers. Drones will be performing bridge assessments following winter storms, monitoring air pollution, delivering live broadcasts or even carrying people.

Drones are seemingly everywhere – but there is still plenty of scepticism. As Richard Andrew Williams rightly points out, there is a host of regulatory, legal and practical barriers to overcome before drones become a fixture of the urban landscape. Our cities have been transformed by a succession of technological breakthroughs over the last two centuries: the arrival of electricity, telephones and of course the car. In the 21st century, drones could have a similarly profound impact, swooping amongst skyscrapers and flying high above our roads and rail lines.

But turning that vision to reality won’t be easy. Indeed, the prospect of packages dropping via parachutes over densely populated areas means we urgently need smart policy development and a wider public conversation about how this technology impacts our lives.

Some challenges still to be addressed are technical in nature: engineering vehicles that can operate quietly and autonomously, designing infrastructure like landing pads or next generation air traffic control systems, creating better sensor technology and emergency landing capabilities, agreeing on technical standards that enable scalability and interoperability. While these questions are largely solvable, not enough has been done on how they operate together, at scale, in real-world environments.

From a policy point of view, the big questions are about whether drones should be restricted to well-defined routes. The Civil Aviation Authority’s Dronecode limits where and how drones can fly – but this is only a start.

Possible exceptions pose thorny ethical debates. For instance, we’ll need to decide how to enable a drone carrying a life-saving organ to surpass standard flight paths, or whether some operators can pay for premium routing priority and faster, more direct routes. Will key parts of the infrastructure like landing pads be open to anyone, as roads are? If so, how will the public pay for and manage them? These considerations echo the current narrative around the autonomy of driverless cars, but are not being given the same attention.

Another cluster of issues centres on real-time data sharing and the appropriate rights of regulators. How will flight paths and movement in real time be shared, to achieve optimal coordination? Should regulators be able to override the drone’s controls? For example, if drones are hacked (as drug traffickers along the US-Mexico border have done) or go haywire, what will trigger decision-makers to step in? As cities from New York and London to Helsinki and Sofia have opened up transport data to improve urban mobility, the data generated from drone-based services can similarly illuminate local movement patterns and services needs – if managed correctly.

Other issues to tackle will be inherently economic. We don’t yet know how drones will influence patterns of economic growth, or particular sectors, such as insurance or logistics. After the US released drone regulations last year, forecasters predicted that the industry will create 100,000 new jobs by 2025 – but others worry that increased automation will leave some workers out in the cold. Before long we’ll also face questions of tax. Will drone usage require registration fees or pay-per-mile arrangements to cover the costs of shared infrastructure?

And most importantly, who will make these decisions?

A century ago the regulation of cars moved forward haphazardly, mainly thanks to problems: crashes, accidents and pollution. All too often, a new technology comes along and cities must find ways to adapt. This is an opportunity to think differently and move the conversation forward, bringing together cities, technologists, regulators and the public.

Drones could be a fantastic boon for cities. but that requires careful thought now – which will be as much about urban planning as it is about technological design.

Geoff Mulgan, Tris Dyson and Kathy Nothstine at innovation foundation Nesta.

Nesta’s Challenge Prize Centre is looking at how drones can enhance city life rather than damage it. It is scoping a series of outcome-based funding opportunities, culminating in live, large-scale and complex urban drones systems demonstrations projects.