NEW DELHI – A new study by Indian researchers has found high concentrations of toxic mercury in the air of India’s capital city, Delhi. According to the research, published in the journal Air Quality, Atmosphere & Health, Delhi’s air contains an average of 6.9 nanograms of mercury per cubic meter, a level significantly higher than the global average for the Northern Hemisphere (1.7 ng/m³) and the Southern Hemisphere (1.3 ng/m³).
The study, conducted by scientists from the Indian Institute of Tropical Meteorology (IITM), Pune, analyzed data on gaseous elemental mercury (GEM) from 2018 to 2024. It found that 72% to 92% of the mercury emissions were linked to human activities, primarily from the combustion of fossil fuels, industrial operations, and vehicular emissions.
While the study found that Delhi’s mercury levels remain below the World Health Organization (WHO) safety thresholds for chronic exposure, the findings underscore the serious public health concerns associated with urban pollution. The researchers emphasized the need for “integrated monitoring and policy interventions” to address the issue.
Despite the high concentrations, the study did contain one piece of positive news: mercury levels in Delhi’s air showed a decrease over the six-year period analyzed, in contrast to earlier measurements.
The report on mercury pollution comes just months after another study revealed the presence of microplastics in Delhi’s air, a separate but equally serious concern. That report found that Delhi residents inhale almost twice as many microplastic particles in the summer as they do in the winter, with a 97% jump in average daily exposure during the hotter months. While no safe threshold for inhaling microplastics has been established, the study warned that constant exposure could lead to serious health issues, including bronchitis, pneumonia, and lung inflammation.