UK Researchers Find Kitchen-Related Indoor Air Pollution Can Exceed Outdoor Pollution By Factor Of Three

by Max Frankel and Stephen Lacey

When we think about air pollution, we often picture busy roads with bumper to bumper car traffic or tall smokestacks releasing plumes of black, sooty smoke — not a roast turkey or a meatloaf.

But a new study out of the UK has found that kitchen appliances, particularly the stove and oven, emit noxious fumes at a rate up to 3 times higher than a busy city street.

The study, done by researchers from the University of Sheffield’s Faculty of Engineering, took measurements from both a rural house and two urban apartments using gas and electric ovens. They tested for harmful pollutants such as Nitrogen dioxide (NO2), Carbon monoxide (CO), Volatile Organic Compounds, and solid particulates small enough to become lodged in the lungs. The NO2 measurements in the apartment with the gas stove well exceeded the UK’s guidelines for indoor pollution and were a full three times higher than the concentrations they found on the street below.

The study is small, but it points to a broader problem of pollution in the built environment.

“We spend 90 per cent of our time indoors and work hard to make our homes warm, secure and comfortable, but we rarely think about the pollution we might be breathing in,” said Vida Sharifi, the professor who led the research.

This has been a major source of discussion within the green building community. As we make our homes and businesses more efficient, what are the consequences of trapping pollutants indoors?

A recent report from the Institute of Medicine looked at the issue:

The outdoor environment permeates indoors in all but maximum-containment laboratory conditions. A building that was tightly sealed as a response to adverse outdoor conditions or because of efforts to reduce energy use might protect occupants from one set of problems but would increase their exposure to another: such buildings tend to have decreased ventilation rates, higher concentrations of indoor-emitted pollutants, and more occupants reporting health problems.

That study was picked up by Fox News as “Green Buildings Hazardous to Health?” As leading green building experts explained, that interpretation was completely wrong. However, it did offer an opportunity to distinguish between an energy efficient building and a truly “green” building that takes a more whole-systems approach to design.

The Rocky Mountain Institute made a great distinction when the report was released:

The issue of buildings and health effects has been studied in detail for many years, and it is well known that energy efficient buildings are not necessarily “healthy.” Ventilation is clearly one area where the two objectives are at odds. Other areas such as daylighting and moisture control are well aligned. These issues simply underscore the need for an integrative design approach to building projects, which enables designers to achieve energy savings as well as many other benefits.

The University of Sheffield study on kitchen emissions is a reminder that we need to think about all forms of pollution — indoor and outdoor — when designing our buildings.

JR: As someone who has researched and written about the benefits of green building design and improving indoor air quality, let me add there is little question that green design boosts both employee health and worker productivity.  As Greg Kats, a former colleague who has studied green building for years has written:

“There have been several hundred peer reviewed studies that document improvements in various aspects of health and productivity and greener more efficient design. Upgrading building energy efficiency typically improves building monitoring and occupant controls, and generally improves indoor air quality, not the other way around.”

4 Responses to UK Researchers Find Kitchen-Related Indoor Air Pollution Can Exceed Outdoor Pollution By Factor Of Three

  1. Chris says:

    It doesn’t help when you burn the food either! Just curious if there are any studies as to if houseplants help clean the house’s air and which ones are most effective?

  2. joyce says:

    There are many studies out there. Here is one found with a quick google:
    NASA did a lot of studies as well for their voyages.

  3. The beauty of the Passive House standard, which we discuss regularly in ArchWeek, is that it combines the efficiency of a super-airtight and highly insulated building (houses or other) with continuous, positive, once through fresh air ventilation.

    This is possible using an efficient air-to-air heat exchanger so most of the heat (or cool) of outgoing air is thermally transferred to incoming air.

    For instance, in the equipment room of a Passive House elementary school for over 1000 students that I toured near Frankfurt, Germany, the largest piece of equipment was the heat exchanger, taking pride of place where most schools in US would have a big boiler.

    Using only about 10% as much energy as a conventional building, the primary heating and cooling units of a Passive House building shrink to almost vestigial.

    With the great ventilation, it’s really a both-and solution!

  4. Were the stoves and ovens studied in this report gas-fired or electric? I suspect that electric stoves and ovens would be significantly less polluting than gas-fired ones.