A new study has revealed that even pristine remote Himalayan regions are no longer untouched by air pollution, with measurable impacts on air quality and potential long-term health risks.
The study highlighted that pollution is worsening, making constant monitoring and specific clean-up plans essential for these sensitive regions, according to information shared by the Ministry of Science and Technology on Wednesday.
Researchers from the Aryabhatta Research Institute of Observational Sciences (ARIES) presented the first year-long observations from January 2021 to June 2022 of 17 non-methane hydrocarbons (NMHCs) at a high-altitude rural site in the Himalayas, Munsyari, a tourist destination influenced by nearby emission sources.
NMHCs are a group of reactive gases emitted from fuel use, vehicles, and other human activities that play a key role in forming ozone and secondary aerosols. It is important to trace them and evaluate their implications for regional air quality and potential impacts on human health.
The researchers observed clear seasonal patterns, with lower NMHC levels during winter and the monsoon and significantly higher concentrations during spring and autumn. It was found that LPG and diesel usage, vehicular emissions and local construction activities as the dominant contributors influencing air quality at this remote site.
“This seasonal variability suggests the combined influence of local emissions, boundary layer dynamics, temperature-driven emissions, upslope winds and biomass burning processes,” the researchers said in their study published by Springer Nature Link.
Importantly, the aromatic hydrocarbons such as benzene and xylene were found to strongly contribute to the formation of secondary pollutants like ozone, known to affect both, climate and human health in the troposphere.
A regional comparison showed that NMHC levels at Munsyari are higher than those observed at another high-altitude site like Nainital, though they remain lower than levels reported in nearby urban centers such as Haldwani and Delhi.
Munsyari provides a unique environment to investigate the influence of local anthropogenic activities, including tourism, as well as regional transport processes on the distribution of NMHCs.
These findings show that human-caused pollution is reaching even remote parts of the Himalayas. While immediate health risks are low, long-term exposure to benzene poses a cancer risk that exceeds safety limits, the Ministry said.
