Switching off gas stoves could help reduce the impact of childhood asthma, according to a new study.
Researchers from the University of Queensland found that for 12.3 per cent of asthma sufferers aged 14 or younger in Australia, the condition was triggered or worsened by exposure to gas stoves.
The researchers also found that exposure to damp housing accounted for worsening conditions in 7.9 per cent of children with asthma.
Dr Luke Knibbs, from the Centre for Air Pollution, Energy and Health Research, and the University of Queensland’s (UQ) School of Public Health, led the study that aimed to find the connection between childhood asthma and the two common indoor exposures in the home.
The study applied a comparative risk assessment approach, which required data on the proportion of the population exposed, the effect estimates for asthma among those exposed, and the total asthma burden in children aged 14 years. The 2011 census was used for the study and counted a population of 4,144,024 children aged 14 years or under.
Damp housing and gas stoves were selected as the two indoor residential exposures to investigate due to exposure to gas stoves being previously associated with childhood asthma, and damp housing (which was defined as the presence of visible mould) has been causally linked with childhood asthma. Both factors are common in Australia and are amenable to interventions for reducing exposure.
Children spend 60–75% of their time indoors at home, the researchers said, which can expose them to several risk factors for asthma, including damp housing and gas stove emissions.
“Cooking with gas releases chemicals such as nitrogen dioxide and formaldehyde, which causes inflammation in the airways and exacerbates asthma,” Dr Knibbs explained. “With 38 per cent of Australian homes using natural gas for stovetop cooking, this is a common problem.”
While the study results suggest that 12.3% of childhood asthma cases could be eased should gas be replaced by a different energy source for cooking, it is stated to be unlikely that a new energy source would not produce indoor emissions, as cooking itself can be a major source of emissions.
The study also identified the presence of dampness in 26.1% of Australian homes.
“Damp homes are quite common around Australia, and living in a damp home can adversely affect children’s lungs,” Dr Knibbs said. “Most parents of children with asthma are aware of ways to minimise exposure to dust mites, pollen and animal hair through vacuuming and replacing carpets with hard flooring, but other indoor exposures are not as well recognised.”
The prevalence of asthma in Australia is among the highest in the world, with 10% of the population currently affected and it is the leading cause of illness in children, according to the study.
— UQ News (@UQ_News) April 15, 2018
Ways to reduce exposure
Dr Knibbs suggests a need for a coordinated national strategy to help increase awareness of indoor environmental exposures including gas stove emissions and dampness as well as the different ways people can reduce exposure in the home.
Using high-efficiency range-hoods could reduce the amount of childhood asthma associated with gas stoves from 12.3% to 3.4%, Dr Knibbs claimed. Although fitting all homes with range hoods would be impractical, improving natural ventilation in all homes should be recommended to reduce exposure to gas combustion products.
“The preferred option is to make sure the range-hood is vented outdoors, rather than a hood that recirculates the air. Even in homes without a range-hood, opening windows during and after cooking can help reduce exposure,” Dr Knibbs suggested.
Range hoods can also help remove cooking-related water vapour, reducing indoor dampness. However, 44% of people in Melbourne with range hoods reported that they did not use them regularly, indicating that their potential health benefits should be communicated to the Australian public.
Dr Knibbs suggests other simple ways to reduce dampness such as better ventilating houses with fresh air (using open windows when conditions allow), using room dehumidifiers and limiting use of clothes dryers indoors.