The effects that urban pollution has on public health is a worldwide concern, and as the population in highly urbanised areas increases, the threat of exposure to urban pollution increases alongside it, a study showed that urban air pollution was responsible for nearly 2 million excess deaths in 2019. This figure alone shows that the air we breathe has vast impacts on our livelihoods.
Why is urban pollution increasing?
One of the main reasons why urban pollution is increasing is due to industrialisation, as the economies of many nations worldwide become highly dependent on industry and manufacturing, whilst the focus and reliance on agriculture decreases.
As a result, many jobs are created within these new industries, which causes migration from rural areas to urban areas due to the new employment opportunities available in the city. People who do not move to the cities commute to work there.
Industrial processes also emit dangerous pollutants into the air which, of course, contribute to urban pollution. Due to this increase, many more people are exposed to air pollution and therefore at risk of respiratory diseases.
As well as this, the increased use of transport, and therefore increased burning of fossil fuels in combustion further contributes to the highly polluted air in urban areas.
How is exposure to urban pollution affecting respiratory disease?
Continual exposure to this heavily polluted air has substantial adverse effects on the respiratory system, which can develop into respiratory disease.
Particles emitted into the air, and then inhaled are deposited in the respiratory tract, and when present in sufficient amounts, these particles can induce inflammation. The extent of pulmonary inflammation depends on the particle's dose and composition.
Studies have shown that exposure to certain particles elicits strong inflammatory responses, such as organic carbon particles and transition metals, from combustion.
Chronic obstructive pulmonary disease (COPD) is a lung disease which is affected by air pollution. People who suffer from COPD are vulnerable, and at a greater health risk from particle pollution than healthy individuals, as subjection to polluted urban air exacerbates the disease and its symptoms.
When an individual with COPD is exposed to particulate pollution, this aggravates the airway and causes it to become inflamed. The narrowing of the airway causes uneven ventilation during inhalation - as a result when pollutant particles are deposited in the respiratory tract, certain regions have excessive particle accumulation which can cause tissue injury.
Asthma is another respiratory disease which is impacted by urban air pollution. However, whilst children and adults alike suffer from asthma, it seems that asthmatic children are more affected by urban air pollution, as compared to adults. This could be due to the anatomy of children, which leads to relatively higher deposition of the pollutant particles in the tracheobronchial region of the lungs.
To conclude, it is evident that human activity is largely responsible for the increase in urban air pollution, which in turn has ongoing negative effects on human health and respiratory disease.