Poor air quality laid bare

A file picture of smog across the Mother City.

Too many fine particles of dust and ash in the air can make us sick, and last year the international guidelines for the amount of particle pollution in the air was exceeded 32 times in the city.

“According to the World Health Organisation, infants and pre-schoolers who are exposed to indoor and outdoor air pollution and second-hand smoke have an increased risk of pneumonia during childhood and a lifelong increased risk of chronic diseases, such as asthma, heart disease, stroke and cancer,” said JP Smith, mayoral committee member for safety and security and social services.

A report on the findings of a Wallacedene air pollution monitoring station – one of 13 stations in the city and surrounding towns – was tabled at the Sub-council 2 meeting on September 19.

The report showed that half of those pollution “exceedences” were localised to Kraaifontein.

According to the report, the “PM10 hour average of 75 micrograms/m3” was exceeded 16 times in Wallacedene between July last year and June this year.

Particulate Matter 10 (PM10) are particles so fine that dozens of them clumped together would be the width of a human hair.

The Department of Environmental Affairs and Tourism, in its Air Quality Standards and Objectives document, says: “There is a concern about PM10 and PM2.5 because of the potential health risks that they pose, given that such fine particles are able to be deposited in and cause damage to the lower airways.”

The document says international guidelines should “not be exceeded more than three times a year”.

It also notes that international studies have linked high concentrations of PM10 and PM2.5 in the air to an increase in hospital admissions for breathing difficulties.

However, Mr Smit said residents need not be alarmed by the stats.

“Data needs to be seen in its specific context,” he said, noting that the standard had been raised from 120 micrograms to 75 in 2015 and that none of the exceedency days were above the old standard.

Many places had more air pollution spikes and it was “highly improbable” to have none in “a developing country such as ours”.

For instance, he said, 105 PM episode days had been recorded a year in Secunda on the Highveld and in Bangladesh, PM levels had frequently exceeded 500 micrograms over 24 hours.

Mr Smith said in Wallacedene, specifically, the particles were made up mostly of pollution and dust.

“When one looks at the sources of particulate matter in Wallacedene, it includes fine dust from open, unpaved areas, smoke particles from open fires – both natural and man-made, vehicle emissions, etc,” he said.

Also unusual was that the “episode days” occurred mostly in summer whereas in prior years it had occurred mostly in winter.

“This suggests that the prevailing drought and other climatic conditions have played a role. The drier the soil and vegetation, the increased likelihood of windblown dust and veld fires,” he said.

Very little could be done to reduce the number of spikes because their root cause was socio-economic.

“The City cannot outlaw the use of wood for braais for instance. Nor can we control the incidence of veld fires or the drought. We can and do regulate vehicle emissions from diesel vehicles; and the City is implementing plans to reduce traffic congestion,” he said.

The City had committed R1.2 million for more air quality monitoring equipment, he said.

“This planned expenditure comes on the back of nearly R1.5m spent in the last financial year to advance the work of our air quality management unit within the specialised environmental health department. This department is a crucial role-player in ensuring that residents and visitors to Cape Town enjoy the right to clean air.”