Low Level Of Benzene Gas Found In New Zealand
Low Level Of Benzene Gas Found In New Zealand - Air Quality Study
SMOKERS and people with internal garages and older, petrol fuelled cars with carburettors are most at risk of inhaling benzene, a Ministry of Health study has shown.
The air quality survey found that New Zealanders are exposed to relatively low levels of benzene overall. It sampled sites in Auckland, Hamilton, Christchurch, Dunedin and Paeroa.
Long-term exposure to high concentrations of benzene increases a person's risk of leukaemia. Acute exposure to high benzene levels can also cause drowsiness, dizziness and headaches.
For the first time the four-year-old study sampled air quality in houses with internal garages, as well as outdoor sites.
Acting Director of Public Health Dr Bob Boyd said it found the highest level of benzene where there were older, regularly used petrol fuelled cars fitted with carburettors in garages connected to houses. Benzene evaporates into the air from petrol, particularly when the engine is warm.
"To reduce any health risk people should keep connecting doors between the house and the garage closed at all times and where possible have the doors sealed to minimise draughts.
"Another good idea is ensuring the garage is well ventilated and letting the car cool down after a drive before closing the garage door."
The only places where benzene was found to exceed international health protection limits outdoors and therefore be at a level potentially hazardous to human health were at kerbside sites in Christchurch and Auckland's Khyber Pass, Dr Boyd said.
Monitoring over the past few years has identified Christchurch to have the highest levels. The Canterbury Regional Council and the Ministry of Transport have initiatives underway to improve air quality and reduce benzene levels.
"For the rest of New Zealand, the amount of benzene is low compared to the limits set by international organisations to protect people's health and also other countries' levels."
Dr Boyd said the report showed that most people breathed in the highest amount of benzene while travelling in motor vehicles. Cigarettes could be the major source of benzene for smokers which was another reason why people should quit smoking, he said.
In houses without connecting garages and smokers, the levels inside were pretty much the same as those in outdoor air.
"But in places where the ambient air benzene concentrations tend to be high, like in Christchurch, emissions from domestic fires and motor vehicles are both significant sources, particularly in winter."