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5 May 2020 Media Release: Effects of the National Lockdown on Air Quality within the Garden Route District

Media Release: Effects of the National Lockdown on Air Quality within the Garden Route District

For Immediate Release
5 May 2020

The major outdoor (ambient) air pollution contributors in the Garden Route district include industrial activities, vehicle emissions and wood burning for household purposes. Due to the current lock-down, only around 20% of these industries have rendered essential services, while vehicle movement decreased by estimate of between 10 and 25%.

According to the World Health Organisation (2013), ambient air pollution, as annual PM2.5, accounted for 3.1 million deaths and around 3.1% of global disability-adjusted life years and the health effects includes respiratory and cardiovascular morbidity, such as aggravation of asthma and respiratory symptoms.

The lockdown has resulted in a reduction of some air pollutants across the district, but not all pollutants react as immediate as others, for instance, carbon monoxide is known to remain in the atmosphere for a couple of years. It is however estimated that there is a 6% global reduction in carbon dioxide emissions due to countries partially shutting down their economies.

As the cooler winter months, approaches some domestic emissions may increase in the informal residential areas, for example, particulate emissions from woodstoves and fires that are used for household purposes. According to experts, economic recovery will receive priority after the lockdown, even if it is to the detriment of the environment. It is therefore vital that authorities involved in air quality management must continue to strive towards a reduction in emissions.

Air quality in George appears to indicate a general decreasing trend in air pollution between 1 March and 27 April 2020 as seen in figures one and two. These results have undergone quality assurance and are compared with time average concentration limits in the National Ambient Air Quality Standards for each criteria pollutant to determine any exceedances or non-compliances with standards.

Demonstrates a decrease in SO2 levels in George, 6µg/m3 to 4µg/m3
Demonstrates a decrease in O3 levels in George, from 12µg/m3 to 2.5 µg/m3

During the development of the GRDM 3rd Generation Air Quality Management Plan, ambient air quality modelling was undertaken in most of the towns in the district. Emissions from industrial activities and traffic were estimated and modelled to identify any possible air quality hotspots for further monitoring. Below are images of dispersion modelling with an estimated 10% of the vehicle data count before the national lock down in Knysna Central Business District and ambient emission with only one listed activity in operation during the NLD in Oudtshoorn.

The impact of industrial activities and vehicle emission are estimated by making use of emission factors obtained from the United States Environmental Protection Agency (USEPA) and modelled by making use of dispersion modelling software.

The Department of Environment, Forestry and Fisheries has developed a country-specific Air Quality Index (AQI) in line with best international practices to simplify the reporting of air quality to the general public. This data can be viewed live by the general public at www.saaqis.environment.gov.za. The AQI is derived from six (i.e. PM10, PM2.5, CO, O3, SO2 and NO2) criteria pollutants, for good air quality (scale 1) to hazardous (10) based on National Ambient Air Quality Standards (NAAQS). Currently, there are three Western Cape Government-owned ambient air quality monitoring stations located in the GRDM, viz. in Mossel Bay, George and Oudtshoorn. The George monitoring station reports live data to the South African Air Quality Information Systems (SAAQIS). The current status in terms of the AQI is one (1 = very good) in George, while for the entire country it is currently 3, which is also considered to be good.


According to satellite images below, obtained from (Copyright (c) 2020 Cameron Beccario 2020), there was a 48% reduction in ground level SO2 pollution on 22 April 2020, when compared with 28 April 2019. The same phenomenon occurred with PM10, which indicates a reduction of almost five times. This correlates well with international studies reported by the international media in respect of PM2,5 concentrations being four times lower than normally experienced in major polluted cities across the world.

Although there is a reduction in air pollution, the effect of air pollution is experienced over years. It is indeed so that the current improvement in air quality is too little over a short period of time to make a significant effect. However, people could again see clear skies over places where it was not possible for the last couple of years. The most valuable benefit therefore would be the awareness that flow from the visible improvement and the subsequent effect on people’s perceptions. The perceptions of affected communities is paramount for effective air quality management.

Reference:
World Health Organisation, Health effects of particulate matter, 2013. Accessed, 30 April 2020. http://www.euro.who.int/__data/assets/pdf_file/0006/189051/Health-effects-of-particulate-matter-final-Eng.pdf

ENDS

Acknowledgements:

  • Western Cape Government, Department of Environmental Affairs and Development Planning (Directorate: Air Quality Management)
  • Letabo Air Quality Specialists
  • South African Air Quality Information System (SAAQIS) – http://saaqis.environment.gov.za/
  • Garden Route District Air Quality Unit
  • Dr Johann Schoeman, Manager: Air Quality Management, Garden Route DM

Issued by the Garden Route District Command Centre

Media Queries: Herman Pieters
Senior Communicator
communications@gardenroute.gov.za