Exposure to air pollution doesn’t just bode ill for a person’s health, a group of economists from the National University of Singapore (NUS) have discovered. It can also impair worker productivity.
“Most of us are familiar with the negative impact air pollution can have on health, but as economists, we wanted to look for other socioeconomic outcomes,” said Alberto Salvo, an associate professor at the school’s department of economics and an author of the study, which was published last week in the American Economic Journal: Applied Economics.
Salvo and his associates, Haoming Liu and Jiaxiu He, homed in on textile factories in China, where they devoted more than a year gleaning information from a dozen firms in four separate provenances before gaining access to data from two facilities: one in Henan and the other in Jiangsu.
Because workers in the mills were paid by the yardage of fabric they made, researchers were able to map the output of specific individuals against the concentration of particulate matter they were exposed to over time.
“Our aim with this research was to broaden the understanding of air pollution in ways that have not been explored,” Salvo said. “We typically think that firms benefit from lax pollution regulations, by saving on emission control equipment and the like; here we document an adverse effect on the productivity of their workforce.”
While pollution levels at the two factory locations fluctuated wildly from day to day, they remained “consistently high,” Salvo said. At one facility, levels of particles less than 2.5 micrometers in diameter (PM2.5) averaged 85 micrograms per cubic meter, or roughly seven times the safe limit set by the U.S. Environmental Protection Agency.
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Unlike with prior studies, Salvo, Liu and He observed that daily oscillations did not throttle worker productivity, but prolonged exposures of up to 30 days, on the other hand, manifested a “definite drop in output.”
“We found that an increase in PM2.5, by 10 micrograms per cubic meter sustained over 25 days, reduces daily output by 1 percent, harming firms and workers,” Liu said. “The effects are subtle but highly significant.”
The economists, being economists, could only speculate on why this was so, though they suggested a mix of physiological and psychological factors might be at play.
“High levels of particles are visible and might affect an individual’s well-being in a multitude of ways,” Liu said. “Besides entering via the lungs and into the bloodstream, there could also be a psychological element. Working in a highly polluted setting for long periods of time could affect your mood or disposition to work.”
The NUS study, researchers say, is the first of its kind because research on working under polluted conditions and how it influences productivity has so far been limited.
One previous study that focused on workers packing fruit in California found a “large and immediate” effect from exposure to ambient PM2.5. When levels rose by 10 micrograms per cubic meter, for instance, workers became 6 percent less productive that same day.
While its estimate is more modest, the team stands behind its calculations which they say more closely hews to their expectations of an industrial juggernaut still in the throes of development.
China’s polluted skies have been a problem for years now, with the country’s mean annual PM2.5 exposure spiking from 48 micrograms per cubic meter in 1990 to 56 in 2016, according to the World Bank, despite stringent regulatory policies enacted five years ago.
“Laborers in China can be working under far worse daily conditions while maintaining levels of productivity that look comparable to clean air days,” Liu said. “If the effect were this pronounced and this immediate, we think that factory and office managers would take more notice of pollution than transpired in our field interviews. Therefore, our finding that pollution has a subtle influence on productivity seems realistic.”