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.

 
 
 
 

Space for 8,000 new homes, most of them affordable... Why it's time to demolish Buckingham Palace

Get a lovely new housing estate, there. Image: Getty.

Scene: a council meeting.

Councillor 1: They say it’s going to cost £369m to repair and bring up to modern standards.

Councillor 2: £369m? Lambeth balked at paying just £14m to repair Cressingham Gardens. They said they’d rather knock it down and start again.

Councillor 1: Then we’re agreed? We knock Buckingham Palace down and build new housing there instead.

Obviously this would never happen. For a start, Buckingham Palace is Grade I listed, but… just imagine. Imagine if refurbishment costs were deemed disproportionate and, like many council estates before it, the palace was marked for “regeneration”.

State events transfer to Kensington Palace, St James’s and Windsor. The Crown Estate is persuaded, as good PR, to sell the land at a nominal fee to City Hall or a housing association. What could we build on roughly 21 hectares of land, within walking distance of transport and green space?

The area’s a conservation zone (Westminster Council’s Royal Parks conservation area, to be exact), so modernist towers are out. Pete Redman, a housing policy and research consultant at TradeRisks, calculates that the site could provide “parks, plazas, offices, cafes and 8,000 new dwellings without overlooking the top floor restaurant of the London Hilton Park Lane”.

Now, the Hilton is 100m tall, and we doubt Westminster’s planning committee would go anywhere near that. To get 8,000 homes, you need a density of 380 u/ha (units per hectare), which is pretty high, but still within the range permitted by City Hall, whose density matrix allows up to 405 u/ha (though they’d be one or two bedroom flats at this density) in an area with good public transport links. We can all agree that Buckingham Palace is excellently connected.

So what could the development look like? Lewisham Gateway is achieving a density of 350u/ha with blocks between eight and 25 storeys. On the other hand, Notting Hill Housing’s Micawber Street development manages the same density with mansion blocks and mews houses, no more than seven storeys high. It’s also a relatively small site, and so doesn’t take into account the impact of streets and public space.

Bermondsey Spa might be a better comparison. That achieves a density of 333u/ha over an area slightly larger than Lewisham Gateway (but still one-tenth of the Buckingham Palace site), with no buildings higher than 10 storeys.

The Buck House project seems perfect for the Create Streets model, which advocates terraced streets over multi-storey buildings. Director Nicholas Boys Smith, while not enthusiastic about bulldozing the palace, cites areas of London with existing high densities that we think of as being idyllic neighbourhoods: Pimlico (about 175u/ha) or Ladbroke Grove (about 230u/ha).


“You can get to very high densities with narrow streets and medium rise buildings,” he says. “Pimlico is four to six storeys, though of course the number of units depends on the size of the homes. The point is to develop a masterplan that sets the parameters of what’s acceptable first – how wide the streets are, types of open space, pedestrian only areas – before you get to the homes.”

Boys Smith goes on to talk about the importance of working collaboratively with the community before embarking on a design. In this scenario, there is no existing community – but it should be possible to identify potential future residents. Remember, in our fantasy the Crown Estate has been guilt-tripped into handing over the land for a song, which means it’s feasible for a housing association to develop the area and keep properties genuinely affordable.

Westminster Council estimates it needs an additional 5,600 social rented homes a year to meet demand. It has a waiting list of 5,500 households in immediate need, and knows of another 20,000 which can’t afford market rents. Even if we accepted a density level similar to Ladbroke Grove, that’s 4,830 homes where Buckingham Palace currently stands. A Bermondsey Spa-style density would generate nearly 7,000 homes.

There’s precedent for affordability, too. To take one example, the Peabody Trust is able to build genuinely affordable homes in part because local authorities give it land. In a Peabody development in Kensington and Chelsea, only 25 per cent of homes were sold on the open market. Similarly, 30 per cent of all L&Q’s new starts in 2016 were for commercial sale.

In other words, this development wouldn’t need to be all luxury flats with a few token affordable homes thrown in.

A kindly soul within City Hall did some rough and ready sums based on the figure of 8,000 homes, and reckoned that perhaps 1,500 would have to be sold to cover demolition and construction costs, which would leave around 80 per cent affordable. And putting the development in the hands of a housing association, financed through sales – at, let’s remember, Mayfair prices – should keep rents based on salaries rather than market rates.

Now, if we can just persuade Historic England to ditch that pesky Grade I listing. After all, the Queen actually prefers Windsor Castle…

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