World Environment Day (WED), first introduced by the United Nations (UN) in 1974, is a day on which individuals, communities, businesses and governments can broaden knowledge and understanding on responsible conduct in preserving and improving the environment. The annual celebration concentrates on a prevalent environmental challenge that requires re-examination in the public arena. In 2019, WED will focus on air pollution.
Facts and Figures
Air pollution links to five main human sources / activities:
- Household: Consequence of burning fossil fuels to cook, heat and light the home. In the UK, domestic solid fuel is the largest source of PM5 (primary particulate matter) with secondary pollutants (volatile organic compounds – VOCs) originating from cleaning and personal care products (Clean Air Strategy 2019).
- Industry: Coal-burning power plants, diesel generators, non-road machinery, industrial and solvent processes all contribute to increasing levels of PM, NOx, VOCs and SO2.
- Transport: About 25% of CO2 emissions are a result of the global transport sector (International Energy Agency). Domestically, transportation contributes to increases in NOx.
- Agriculture: The rearing of livestock and the burning of agricultural waste leads to increases in methane (CH4) and ammonia (NH3). Methane is a potent greenhouse gas that also contributes to ground-level ozone.
- Waste: Globally, about 40% of waste is openly burned which leads to the release of pollutants into the atmosphere such as methane and black carbon (UN).
Figure 1 below illustrates sources of air pollutants and the associated negative impacts.
Human Health and Environmental Impacts
The pollutants associated with poor air quality negatively impact both human health and the environment. Population groups that are vulnerable and/or more susceptible to the negative effects of poor air quality are:
- Pregnant women;
- Young children; and
- Individuals with existing cardiovascular or respiratory diseases / conditions (i.e. heart disease and/or asthma).
The UN reports that 9 out of 10 people breathe in polluted air and the impacts of this can be devastating and sometimes fatal. For example, the High Court recently re-opened a case concerning the death of a young girl in South London in which new evidence indicates unlawful levels of pollution may have contributed to her fatal asthma attack (BBC UK).
Environmental impacts associated with pollutants that contribute to poor air quality are vast and oftentimes irreversible:
- Increased acidification and nitrogen in habitats can lead to decreases in biodiversity;
- Increased levels of sulphur dioxide can contribute to the formation of acid rain; and
- VOCs reacting with other pollutants can lead to the production of ground-level ozone (O3) which decreases plant growth and contributes to global warming.
In addition to the above, recent studies based on atmospheric modelling have concluded that air pollutants are not restricted to international boundaries and, therefore, not localised (Smithsonian). This means that pollution in one country has the potential to travel and impact the greenhouse gas effect in another country while also increasing the likelihood of extreme weather events.
Next week’s blog will examine the various initiatives and innovations being implemented to combat negative contributions to air quality.