Temporary reduction in fine particulate matter due to 'anthropogenic emissions switch-off' during COVID-19 lockdown in Indian cities

The COVID-19 pandemic elicited a global response to limit associated mortality, with social distancing and lockdowns being imposed. In India, human activities were restricted from late March 2020. This 'anthropogenic emissions switch-off' presented an opportunity to investigate impacts of COVID-19 mitigation measures on ambient air quality in five Indian cities (Chennai, Delhi, Hyderabad, Kolkata, and Mumbai), using in-situ measurements from 2015 to 2020. For each year, we isolated, analysed and compared fine particulate matter (PM2.5) concentration data from 25 March to 11 May, to elucidate the effects of the lockdown. Like other global cities, we observed substantial reductions in PM2.5 concentrations, from 19 to 43% (Chennai), 41-53% (Delhi), 26-54% (Hyderabad), 24-36% (Kolkata), and 10-39% (Mumbai). Generally, cities with larger traffic volumes showed greater reductions. Aerosol loading decreased by 29% (Chennai), 11% (Delhi), 4% (Kolkata), and 1% (Mumbai) against 2019 data. Health and related economic impact assessments indicated 630 prevented premature deaths during lockdown across all five cities, valued at 0.69 billion USD. Improvements in air quality may be considered a temporary lockdown benefit as revitalising the economy could reverse this trend. Regulatory bodies must closely monitor air quality levels, which currently offer a baseline for future mitigation plans.

Stakeholder perceptions of lowering the blood alcohol concentration standard in the United States

PURPOSE

This study sought to better understand the past change in the legal blood alcohol concentration (BAC) standard from 0.10% to 0.08% in the United States, as well as explore stakeholder perceptions about potential health and other impacts of further lowering the standard below 0.08%.

METHODS

In-depth interviews were conducted with representatives of 20 organizations considered to have an interest and investment in the potential impacts of strategies to decrease alcohol-impaired related crashes and injuries. Interviews were conducted by a trained moderator, using a structured guide.

RESULTS

Themes from the interviews are presented for several discussion topics explored for both the earlier change in the legal BAC limit from 0.10% to 0.08% and a potential lowering of the limit below 0.08%. Topics included arguments for and against change; organizational position on the change; stakeholders on both sides of the issue; strategies to support or oppose the change; health and economic impacts; and enforcement and adjudication challenges.

CONCLUSIONS

Collectively, results suggest that moving the BAC standard below the current level will require considerable effort and time. There was strong, but not complete, agreement that it will be difficult, and maybe infeasible in the short-term, for states to implement a BAC standard lower than 0.08%.