Feeling less productive? Blame it on the air: NUS study

WONG PEI TING Today Online 3 Jan 19;

SINGAPORE — Exposure to air pollution over several weeks is not just unhealthy, it can also affect worker productivity, according to a study by the National University of Singapore (NUS).

Employee productivity dips by 1 per cent when the PM2.5 — a fine particulate matter less than 2.5 microns in size — in the air increases by 10 micrograms per cubic metre and stays at that level for 25 days, the study found.

The NUS team spent more than a year gathering information from factories in China and scrutinising the output levels of two textile mills at Henan and Jiangsu. The findings from the study were published in the American Economic Journal: Applied Economics on Thursday (Jan 3).

NUS economist Alberto Salvo, who authored the study, told TODAY that the findings could be applicable to Singapore even on normal days when the country is not hit by haze.

Productivity here could drop by 1 per cent if the PM2.5 increases from 15 micrograms per cubic metre to 25 micrograms per cubic metre if employees work in a “still atmosphere, with poor ventilation” over a fortnight or a month, said the associate professor.

As a gauge, hourly PM2.5 levels in the central parts of Singapore on Thursday hovered between 14 micrograms per cubic metre and 25 micrograms per cubic metre.

Those who work in air-conditioned offices were not spared, added Assoc Prof Salvo, noting that his team studied Chinese workers who operated on factory floors that were air-conditioned in the summer when temperatures rise to and beyond what Singapore experiences.

While a 1 per cent impact on productivity might seem inconsequential, Associate Professor Liu Haoming, who was part of the NUS team, said the effects were “subtle but highly significant”.

This was because the results from the study demonstrated to factories that those with lax pollution controls, or have cut back on emission control equipment, were not helping their own bottom lines.

Pollution levels were consistently high at the mills studied, with one of them recording a PM2.5 level averaging 85 micrograms per cubic metre — about seven times the safe limit set by the United States Environmental Protection Agency.

While pollution levels varied significantly from day to day, the NUS team found that the fluctuations did not immediately affect the productivity of workers. Rather, they established that a definite drop in output could be seen when examining more prolonged exposures of up to 30 days.

Assoc Prof Liu said their findings reflect a “psychological element” to the effects of air pollution.

“High levels of particles are visible and might affect an individual’s well-being in a multitude of ways,” he added.

“Besides entering via the lungs and into the bloodstream… working in a highly polluted setting for long periods of time could affect your mood or disposition to work.”

Touted as a first-of-its-kind study examining prolonged exposure to air pollution, NUS said that there is “very limited” research on how living and working in such a polluted environment affects productivity, partly because worker output is difficult to quantify.

All the data collected as part of the study will be made accessible “to serve as a resource for other researchers to accelerate progress in this topic”.

Prolonged exposure to air pollution lowers worker productivity: NUS study
Joanna Seow Straits Times 3 Jan 19;

SINGAPORE - Living and working in a polluted environment is not just bad for health, but also bad for productivity, a new study has found.

"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," said Associate Professor Alberto Salvo, one of the three economists who did the study.

Daily output falls by 1 per cent when there is a rise in PM2.5 levels by 10 micrograms per cubic m (mcg/m3) sustained over 25 days, said the researchers from the National University of Singapore (NUS) economics department.

PM2.5 readings measure the concentration of tiny particles less than 2.5 micrometres in diameter - or about one-thirtieth the diameter of a human hair - in the air.

Long-term exposure to them on a regular basis has been linked to increased risk of death from complications such as cancer or heart disease.

But research on how it affects productivity is very limited, partly owing to worker output being difficult to quanitfy, said an NUS statement on Thursday (Jan 3).

To study the issue, Prof Salvo, Associate Professor Liu Haoming and Dr He Jiaxiu interviewed managers at 12 companies and gathered data from two textile mills in China from January 2014 to May 2015. The trio compared the number of pieces of fabric each worker produced each day against the level of air pollution the worker was exposed to over time.

They found that unlike in previous literature, workers' productivity was not immediately affected by daily fluctuations in pollution. But prolonged exposure of up to 30 days caused output levels to drop.

On possible reasons for the decline, Prof Liu said that besides the physiological impact of pollution, there could also be a psychological element to it. "Working in a highly polluted setting for long periods could affect your mood or disposition to work," he said.

The results of the study, which were controlled for factors like regional economic activity, were published in the American Economic Journal: Applied Economics on Thursday .

Prof Liu said the team chose China for the study as they needed a larger variation of air pollution levels to probe the impact on workers.

The results also apply in Singapore, where pollution levels are generally lower, he added.

Prof Salvo said that although very high levels of PM2.5 in Singapore, caused by transboundary haze, have not been frequent, the findings suggest productivity could be hurt.

Even during normal periods, it could decline by 1 per cent if the particle levels were raised over a fortnight or month owing to the air being more still, even if the change was only from 15 to 25 mcg/m3, he said.

As at 7pm on Thursday, a regular, non-hazy day, the concentration of PM2.5 here ranged from 14 to 19 mcg/m3 in different parts of the island.

Given the findings, companies in Singapore can encourage workers to reduce their exposure to the outdoor air if pollution levels rise, said Prof Liu. "They could encourage workers to work indoors or close the windows when they are at home."

Assoc Prof Salvo added: “We wanted to share all the information we gathered so that other researchers may use it well, hopefully adding to this literature’s long-run credibility.”