Bloomberg - The welcome return of China’s economy is bringing with it some unwelcome company, as air pollution levels have returned to pre-lockdown levels across the country.

Major pollutants have exceeded concentration levels from a year ago for the first time since the start of Covid-19 lockdowns in January, according to a new report from Centre for Research on Energy and Clean Air. The rebound from declines of as much as 40% come as factories restart and traffic returns to city roads.

Soaring smog indicates that the economic recovery has been led by the country’s most highly polluting sectors, said Lauri Myllyvirta, the center’s lead analyst. It also underscores the fear of many environmentalists that any post-virus stimulus package will lean heavily on heavy industry, similar to what happened after the 2008 financial crisis.

“Rebounding air pollutant levels are a demonstration of the importance of prioritizing green economy and clean energy in the recovery from the Covid-19 crisis,” Myllyvirta said in the report. “All eyes are on China as the first major economy to return to work after a lockdown.”

Nitrogen dioxide and ozone readings averaged over 30 days now exceed last year’s levels, according to data from 1,500 air-monitoring stations set up across the country, according to the center. Sulfur dioxide and air particulate levels are higher than in January when the government began restricting movement to slow the spread of Covid-19.

During the lockdown, nitrogen dioxide levels in China dropped by 40% while carbon dioxide emissions fell by a quarter.

Pollution has increased more in areas where coal-burning is the major source of energy, according to the report. In cities like Beijing and Shanghai, where efforts have been made to replace coal with cleaner forms of power, pollution still remains lower than last year’s levels.