Clearing the air through the revised WHO guidelines

Earlier this week, the World Health Organization (WHO) announced new air quality guidelines that aid countries in defining air quality levels that protect public health.

The first revision of the guidelines since 2005, this review benefited from a wealth of new scientific evidence generated in the interim period across developed and developing countries. The data showed that severe impacts of particulate and gaseous pollutants on health occur even below levels previously considered acceptable by health scientists.

These new guidelines also come weeks after the government announced the formation of a panel under the environment ministry to review India’s National Ambient Air Quality Standards (NAAQS). Last revised in 2009, NAAQS, as they stand, are exceedingly lenient, given what we have learnt in the last decade about the impact of air pollution on premature death and illness in India and elsewhere. Compared to the updated WHO guidelines, NAAQS levels for PM2.5 alone will be eight-fold higher for 24-hour exposures, and four-fold higher for annual exposures. Indian lungs are no different from any others, so there is no scientific rationale for such a vast discrepancy.

There are key process lessons that can be learnt from the way the WHO and other agencies around the world, including the United States Environmental Protection Agency, conduct such reviews. At the centre is scientific evidence that is factored into decision-making and the role of key stakeholders at various stages in the process.

It has not been clear what scientific and epidemiological evidence was considered in decision-making for the previous revision of NAAQS in 2009. While this may have been due to a dearth of local data on the health effects of air pollution at the time, the last 12 years have yielded considerable evidence on the impact of air pollution exposure on cardiovascular and metabolic diseases.

Health impact studies, led in part by the Indian Council of Medical Research, have shown that ambient PM2.5 was responsible for almost a million premature deaths in India (2019). Clarity on how these significant scientific advances will be factored in must be an essential aspect of this process.

NAAQS revisions must also ensure that a diversity of voices are represented in deliberations, including from atmospheric science, public health, policy, law, and civil society. Greater inclusivity and transparency must be the hallmarks of this process.

WHO guidelines are a clear nudge from the health sector towards the deep decarbonisation of our economy necessary to achieve both climate and air pollution goals. However, as things stand, most — if not all — Indian cities struggle to meet NAAQS, let alone the updated WHO guidelines. Even the targeted 30% reduction from 2017 levels under NCAP, if met, will only provide marginal benefits in improving health.

Originally published in Hindustan Times on September 25, 2021.

Environmentality is a collection of ideas, perspectives, and commentary by researchers at the Initiative on Climate, Energy and Environment, Centre for Policy Research, New Delhi. Views and opinions expressed in this blog are solely those of the authors. They do not represent institutional views.