Thimphu’s air quality defies WHO permissible limit

The annual average level of PM 10 (particulate matter with a diameter of 2.5-10 micrometers) has been increasing and its levels have consistently been higher than the standards set by the World Health Organization (WHO).

WHO’s standards is 20 microgram per cubic meter (µg/m3), however, Thimphu recorded higher than 30 µg/m3 since 2009 and recorded higher than European Union limits of 40 µg/m3 in year 2010, 2012, 2014 and 2015, according to Asian Development Bank’s (ADB) ‘Bhutan Vehicle Emission Reduction Road Map and Strategy, 2017–2025’.

The major components of PM are sulfate,

nitrates, ammonia, sodium chloride, black carbon, mineral dust, and water.

There is good evidence of the effects of short-term exposure to PM10 on respiratory health, according to WHO.

The emissions levels are likely to triple by 2030, if no action is taken and would cause severe air pollution posing risks to people’s health and environment and, a massive increase in carbon dioxide (CO2) emissions, the report states.

The major sources of air pollutants are passenger cars and heavy-duty vehicles (HDVs) including diesel-powered large and medium sized trucks and buses accounting to 73% of the total number of vehicles in the country based on Road Safety and Transport Authority in June 2015.

The same year, HDVs were responsible for about 70% to 90% of local pollutants and nearly 60% of GHGs in the country.

The strategy report finds out based on the current trends of vehicle acquisition and fuel import standards, and without any policy interventions, vehicle inventory in the country may increase from around 84,000 units in 2016 to 180,000 units by 2030.

With this, emissions from the domestic transport sector (i.e. excluding Indian vehicles, called re-export) may reach 660,000 tons of carbon dioxide equivalent (tCO2 e) in 2030.

The country’s Second National Communication to the United Nations Framework Convention on Climate Change (UNFCCC) in 2011 reported that GHG emissions from the transport sector accounted for about 20% of the country’s total emissions in 2000.

By the end of 2012, the sector’s percentage share increased to about 30% of the total emissions. In the coming years, GHG emissions from the transport sector are expected to grow further as vehicle ownership is increasing at an average rate of 15% per annum.

The report recommends five core policy interventions that will be important for vehicle emission reduction in Bhutan.

The policy emphasizes on import of low-sulfur fuels, as sulfur is a pollutant and its presence in fuels prevents the adoption of major pollution control technologies such as diesel particle filters, particulate filters, and nitrogen oxide (NOx) absorbers.

As the country has no fuel refineries and imports fuel from India, India’s working on lowering the sulfur content of its fuel as 50 parts per million (ppm) by 2017 and 10ppm by 2021 would cut down Bhutan’s sulfur dioxide(SO2) emissions by 80% in 2018 and 95% by 2021.

Moreover, the report recommends issuing a regulation that requires all fuels imported from India to comply with the originating country’s fuel standards, continues testing fuel quality to help ensure compliance, and upgrades its fuel quality testing procedures.

The other interventions would be to update vehicle emission standards aligned to India as an importer of vehicle to Bhutan has introduced measures to implement standards equivalent to Euro 4 by 2018 and Euro 6 by 2021.

Implementing the policy would lower the PM emission by 65% and NOx emissions by 40% by 2030 compared to 2015 levels and GHG emissions will be reduced with less black carbon emissions.

To upgrade vehicle emission inspection system, Bhutan has to improve its regulations, strengthen enforcement, and enhance the testing procedures and execution to minimize errors and prevent high-emitting vehicles from passing the vehicle emission inspection test.

There is also need of restriction of diesel cars and light-duty vehicles as diesel engine results in high PM and nitrogen dioxide (NO2) emissions.

The policy is to limit use of diesel to large trucks, buses, and mobile machinery and disallowing the registration and use of diesel passenger cars, taxis, and light vehicles with a gross vehicle weight of less than 3.5 tons.

The implementation of this policy could lower Bhutan’s urban air pollution from PM and SO2 emissions by half, and NO2 emissions by one-third, by 2030.

In addition, on promoting low carbon vehicles as hybrid, plug-in hybrid, electric cars emit low CO2 throughout their lifespan compared to diesel and gasoline powered vehicles.

Government has to do more on providing substantial incentives and reducing taxes on low carbon vehicles.

The Road Safety and Transport Authority recorded 103,814 vehicles in the country with highest in Thimphu with 53,999 as of June 30 this year.

pic courtesy: google

Thukten Zangpo from Thimphu