Frying steak on
gas hob 'may increase risk of cancer'
Reported February 18, 2010
Using a gas hob appeared to be worse and created more of
the harmful particles than using an electric one, the study conducted in
Norway found.
The researchers said exposure to the fumes should be kept to a minimum and
added that professional chefs were at particular risk.
Cooking fumes have been shown to cause changes in DNA that may lead to
cancer and may increase the risk of lung cancer.
The International Agency for Research on Cancer recently classified
high-temperature frying as 'probably carcinogenic to humans', the same
category as diesel and some insecticides.
The researchers said an increased risk of respiratory tract cancer in cooks
and bakers has been reported and the compounds which have been identified
are polycyclic aromatic hydrocarbons (PAHs), heterocyclic amines and higher
aldehydes.
These compounds were found in the breathing zone of cooks when frying, the
research found.
The study involved frying 17 beefsteaks on a gas or electric hob
consecutively for 15 minutes using margarine or soya bean oil.
The frying was conducted in a specially built kitchen desiogned to mimic a
commerical restaurant kitchen with an extractor over the hob.
The study is published in the journal Occupational and Environmental
Medicine found that the levels of polycyclic aromatic hydrogcarbons produced
during the experiments were below accepted occupational safety thresholds.
But they added that there were other particles found in
the fumes for which there is no established safe level.
Ann Kristin Sjaastad, lead author from Norwegian University of Science and
Technology, in Trondheim, wrote in the journal: "The measured levels of
total particles and PAHs for the cooks in our study are far below the
Norwegian occupational exposure limits for nuisance dust.
"However, cooking fumes consist of a mixture of toxic and mutagenic
compounds, including mutagenic aldehydes and heterocyclic amines with no
known dose-response relationship, so exposure to cooking fumes should be
reduced as much as possible."
She added: "Our study shows that using a gas stove instead of an electric
stove results in higher levels of PAHs, aldehydes and particles.
"This is presumed to be due to the higher temperature of the gas flame
resulting in more thermal degradation products. The higher level of
ultrafine particles may also be due to the gas flame itself and not just a
result of the cooking process."
Dr Deborah Jarvis, who works at the National Heart and Lung Institute and
within the Medical Research Council and Health Protection Agency Centre for
Environment and Health, based at Imperial College London, said: “There have
been large scale studies to see whether people who cook with gas have more
breathing problems - such as coughs, infections and asthma - than those who
cook with electricity. Results from these studies are inconsistent.
"This new study may help us understand why these inconsistencies occur. The
public health message to the general public remains the same – keep your
kitchen well-ventilated when cooking, and make sure all your gas appliances
are well maintained.”
Prof Roy Harrison, Professor of Environmental Health, Birmingham University,
said: “There are no big surprises in this work. Cooking, and especially
frying, have long been known to be a source of carcinogenic chemicals and
ultrafine particles. The health consequences, if any, remain uncertain.”
Source : Telegraph Media Group Limited
