Thesis Abstract

Air pollution is a significant environmental and public health issue affecting cities worldwide. The continuous increase in urbanization and industrialization has led to a rise in air pollution levels, posing a serious threat to the health of city dwellers. This research project aims to explore the ongoing challenges and health impacts of air pollution in the world's cities. The sources of air pollution in urban areas are diverse, ranging from vehicle emissions, industrial activities, to household combustion of solid fuels. These sources release a variety of pollutants such as particulate matter (PM), nitrogen oxides (NOx), sulfur dioxide (SO2), carbon monoxide (CO), volatile organic compounds (VOCs), and heavy metals into the atmosphere. The accumulation of these pollutants in the air can lead to the formation of smog and haze, which not only reduce visibility but also have adverse effects on human health. Exposure to air pollution has been linked to a wide range of health problems, including respiratory diseases, cardiovascular diseases, and even premature death. Particulate matter, especially PM2.5 and PM10, can penetrate deep into the lungs and enter the bloodstream, causing inflammation and oxidative stress in the body. Prolonged exposure to high levels of air pollution has also been associated with an increased risk of developing asthma, bronchitis, and other chronic respiratory conditions. Vulnerable populations such as children, the elderly, and individuals with pre-existing health conditions are at a higher risk of suffering from the health effects of air pollution. Children exposed to air pollution may experience stunted lung development and cognitive impairments, while the elderly are more susceptible to cardiovascular diseases exacerbated by poor air quality. Moreover, individuals living in socioeconomically disadvantaged neighborhoods often face higher levels of air pollution due to proximity to industrial sites and busy roadways, further exacerbating health disparities. Addressing the issue of air pollution requires a multi-faceted approach involving government regulations, technological advancements, public awareness campaigns, and community engagement. Strategies such as promoting clean energy sources, improving public transportation systems, and implementing emission control measures can help reduce air pollution levels in cities. Additionally, monitoring air quality, conducting health impact assessments, and implementing early warning systems can aid in mitigating the health risks associated with air pollution exposure. In conclusion, air pollution remains a pressing health threat in the world's cities, necessitating immediate action to protect public health and the environment. By raising awareness, implementing effective policies, and fostering collaboration among stakeholders, we can work towards creating cleaner and healthier urban environments for current and future generations.

Thesis Overview

27 SEPTEMBER 2016 | GENEVA – A new WHO air quality model confirms that 92% of the world’s population lives in places where air quality levels exceed WHO limits*. Information is presented via interactive maps, highlighting areas within countries that exceed WHO limits.

“The new WHO model shows countries where the air pollutioni danger spots are, and provides a baseline for monitoring progress in combatting it,” says Dr Flavia Bustreo, Assistant Director General at WHO.

It also represents the most detailed outdoor (or ambient) air pollutioni-related health data, by country, ever reported by WHO. The model is based on data derived from satellite measurements, air transport models and ground station monitors for more than 3000 locations, both rural and urban. It was developed by WHO in collaboration with the University of Bath, United Kingdom.

Some 3 million deaths a year are linked to exposure to outdoor air pollutioni. Indoor air pollution can be just as deadly. In 2012, an estimated 6.5 million deaths (11.6% of all global deaths) were associated with indoor and outdoor air pollution together.

Nearly 90% of air-pollution-related deaths occur in low- and middle-income countries, with nearly 2 out of 3 occurring in WHO’s South-East Asia and Western Pacific regions.

Ninety-four per cent are due to noncommunicable diseases – notably cardiovascular diseases, stroke, chronic obstructive pulmonary disease and lung cancer. Air pollution also increases the risks for acute respiratory infections.

“Air pollution continues take a toll on the health of the most vulnerable populations – women, children and the older adults,” adds Dr Bustreo. “For people to be healthy, they must breathe clean air from their first breath to their last.”

Major sources of air pollution include inefficient modes of transport, household fuel and waste burning, coal-fired power plants, and industrial activities. However, not all air pollution originates from human activity. For example, air quality can also be influenced by dust storms, particularly in regions close to deserts.

The model has carefully calibrated data from satellite and ground stations to maximize reliability. National air pollution exposures were analysed against population and air pollution levels at a grid resolution of about 10 km x 10 km.

“This new model is a big step forward towards even more confident estimates of the huge global burden of more than 6 million deaths – 1 in 9 of total global deaths – from exposure to indoor and outdoor air pollution,” said Dr Maria Neira, WHO Director, Department of Public Health, Environmental and Social Determinants of Health. “More and more cities are monitoring air pollution now, satellite data is more comprehensive, and we are getting better at refining the related health estimates.”

The interactive maps provide information on population-weighted exposure to particulate matter of an aerodynamic diameter of less than 2.5 micrometres (PM2.5) for all countries. The map also indicates data on monitoring stations for PM10 and PM2.5 values for about 3000 cities and towns.

“Fast action to tackle air pollution can’t come soon enough,” adds Dr Neira. “Solutions exist with sustainable transport in cities, solid waste management, access to clean household fuels and cook-stoves, as well as renewable energies and industrial emissions reductions.”