Commercial kitchen staff exposed to high air pollution, US study finds

A first-of-its-kind US study has found that people who cook for a living in commercial kitchens can be exposed to high levels of air pollution at work, and that the pollution also drifts into areas where diners eat.

Researchers at the non-profit research institute PSE Healthy Energy measured air quality in 27 kitchens. The sample covered fine-dining and casual full-service restaurants, pizza and Chinese restaurants, catering facilities, and kitchens in senior-living communities, universities and schools. In the UK, 3.6 million people work in catering and hospitality; the US figure is estimated at close to 16 million.

The kitchens met US legal limits for air pollution in workplaces, but nitrogen dioxide in 17 of them was higher than World Health Organization guidelines for indoor air. All 17 cooked with fossil gas or propane. Nitrogen dioxide is also found in diesel exhaust and has led many UK and European cities to introduce clean air and low-emission zones.

Electric kitchens fared best

Three all-electric kitchens — a full-service restaurant, a school cafeteria and a conference centre kitchen — took part in the study and recorded the lowest air pollution, indicating benefits from decarbonising catering and ending fossil-gas combustion. They also had the lowest temperatures, an obvious gain for staff welfare. This summer's European heatwave forced some UK restaurants to cut hours or close in sweltering conditions.

Chef Christopher Galarza, who worked with the researchers, described shifts that ended "drenched in sweat, dehydrated and physically spent" because of the heat in kitchens.

Air pollution did not stay in the kitchen, the study found: median concentrations in dining areas were greater than WHO guidelines for outdoor air pollution. First author Dr Yannai Kashtan said it was difficult to put the relative risk to diners in context, but that diners in a restaurant with gas-fired appliances could be exposed to elevated levels of nitrogen dioxide.

Pilot lights burning round the clock

One result surprised the research team. In two-thirds of the gas kitchens, pollution was higher overnight and in the early morning, when all the appliances were off, because pilot lights burn continuously whether or not ventilation is running.

Senior author Dr Drew Michanowicz said commercial-grade cooking appliances were not covered by the US energy efficiency regulations that phased out pilot lights in homes, and that a full-service kitchen with ranges, griddles, fryers, ovens, steamers and broilers can have 20 to 30 small flames burning constantly.

In the UK, many commercial kitchens have automatic systems that cut off gas when ventilation is not operating. In the study, pollution from pilot lights spread into dining areas, increasing exposure for cleaners and other workers and raising health risks for other people in multi-use buildings.

Source: The Guardian.