Vehicular fumes escalate deaths and illness: New global study

Diesel vehicles responsible for nearly half the world's premature deaths. Delhi ranks sixth
Credit: Getty Images
Credit: Getty Images

The first-ever comprehensive assessment of health impacts of global transport emissions, just released by the United States (US)-based International Council of Clean Transportation (ICCT), has exposed the lethal health effects of vehicular fumes across major vehicle markets of the world.

Exhaust from on-road diesel vehicles is responsible for nearly half of the impacts —181,000 premature deaths worldwide, and two-thirds in India, France, Germany, and Italy. Among the 100 major urban centres assessed for transport sector-related deaths globally, New Delhi ranks sixth. 

It is worrying that the global health burden of only on-road diesel vehicles is 68 per cent higher than previously estimated for diesel and nitrogen oxide emissions. This estimate now includes the effects of tailpipe PM2.5 as well.

This new study — A global snapshot of the air pollution–related health impacts of transportation sector emissions in 2010 and 2015 — has been conducted by the researchers from the ICCT, George Washington University Milken Institute School of Public Health, and the University of Colorado Boulder and has linked vehicle emissions, air pollution, and epidemiological models to estimate health impacts at the global, regional, national, and local levels in 2010 and 2015.

This study shows how the transport sector health burden is linked with vehicles’ contribution to elevated levels of particulate matter nitrogen oxides and ozone. This has exposed the widely damaging impacts of vehicles that include tailpipe emissions, evaporative emissions, resuspension of road dust, and particles from brake and tyre wear. Vehicles also create the attendant problems of noise, physical activity effects, and road injuries.

This study, while estimating the total health burden from the transportation sector as a whole, has also gone more granular in capturing health impacts by sub sectors of transportation including on-road diesel vehicles, on-road non-diesel vehicles, shipping, and non-road mobile sources that combine agricultural and construction equipment and rail transportation.

Dubious tally

Global transportation emissions in 2010 and 2015 contributed 361,000 and 385,000 PM2.5 and ozone-attributable premature deaths respectively. Together, PM2.5 and ozone concentrations from transportation emissions resulted in 7.8 million years of life lost and approximately $1 trillion in health damages globally in 2015. This study has used methods that are aligned with the Global Burden of Disease Study 2017, and the data resources of Institute for Health Metrics and Evaluation, 2018.

In 2015, 84 per cent of global transportation-attributable deaths occurred in G20 countries, and 70 per cent occurred in the four largest vehicle markets of China, India, the European Union (EU), and the United States. However, between 2010 and 2015, the global health risk from the transportation sector has stabilised overall (11.7 per cent of global PM2.5 and ozone mortality in 2010 and 11.4 per cent in 2015). This stabilisation is largely due to the transportation emissions reductions in leading regulatory markets with the advancement of emissions regulations.

There is however, variation in trends among the four largest markets: From 2010 to 2015, transportation-related deaths have declined by 14 per cent and 16 per cent in the EU and US due to improvement in emissions standards and fuel quality and new vehicle emissions. For example, Euro VI for heavy-duty vehicles in EU and Tier 3 for light duty vehicles in the US have reduced emissions of PM2.5 by 99 per cent or more.

However, health burden from transport increased by 26 per cent in China and India. This increase indicates that the growth in transportation activity exceeded the reductions from emission control policies between 2010 and 2015. The new changes including recent decisions on advancing emissions standards have just about occurred. But it is too early to capture the impact of this change in India, China, Mexico, and Brazil, which will take effect between 2020 and 2023.

Urban centres: More vulnerable

This study has further assessed 100 major urban areas where transportation emissions and exposure are high globally. The urban areas with the highest number of transportation-related air pollution deaths reflect the largest population and transportation emissions. The top 10 in order for 2015 were Guangzhou, Tokyo, Shanghai, Mexico City, Cairo, New Delhi, Moscow, Beijing, London, and Los Angeles. Thus, New Delhi ranks sixth among the 100 urban centres with highest transport emissions-related health burden. This needs to inform policies in India. 

By contrast, when normalised by population, the urban areas with the highest number of transportation-attributable air pollution deaths per 100,000 people are mainly in Europe. In fact, the number of transportation-related deaths per 100,000 population in London and Paris are approximately 2 to 3 times higher than the global average.

Diesel: The Devil

This study reaffirms the deadly effects of diesel emissions. Among the four transportation subsectors analysed, on-road diesel vehicles have been found to be contributing the most to pollution from the transport sector and associated disease burdens.

This was particularly the case in the EU, where on-road diesel vehicles accounted for 60 per cent of transportation-attributable PM2.5 in 2015. Europe has experienced very high level of dieselisation of the passenger car fleet, coupled with chronic elevated emissions of nitrogen oxides from diesel passenger cars meeting Euro IV- Euro VI and buses and trucks certified to Euro IV and Euro V. This is why the 10 countries in 2015 with the highest transportation-attributable fractions of PM2.5 from all sources were all in Europe.

Globally, and in each trade bloc, diesel emissions were the dominant contributor to total transportation-attributable health impacts in 2015. On-road diesels are the largest contributor to transportation-attributable PM2.5 and ozone burdens in nearly all trade blocs. The on-road diesel vehicle fraction is by far the highest in the EU and European Free Trade Association trade bloc, representing 15 per cent of the combined PM2.5 and ozone burden from all sources. On-road diesels also contribute more than any other subsector to black carbon concentrations and transport-related fraction in major vehicle markets. This has both, health and global warming impacts.

This has serious implications for India that is in grip of dieselisation. Earlier, the World Health Organization has linked diesel emissions to lung cancer and branded it as a Class I carcinogen. Several other studies have established serious health consequences of diesel emissions.

Act now

This study has significantly sharpened the focus on the serious health risk posed by vehicles. Ray Minjares the Clean Air Program Lead at the ICCT says, “Monitoring and evaluating impacts of harmful environmental exposures is a key function of public health research. This study fills a void in this research and shapes strategic thinking around the policies and trends that shape our work going forward.”

Clearly, these new evidences have huge policy implications for India that is motorising and dieselising rapidly. Usually higher relative contribution of other sources of pollution overwhelms the contribution of the transport sector to health burden in India and other developing countries. But that should not detract India from the urgent need to take stringent action to curb dieselisation and reduce transport sector pollution effectively — across all subsectors of transport — to cut toxic exposures. Vehicles are responsible for very high exposures and health burden in our cities.    

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