Humid houses pose health hazards

Babs Verblackt, CNS Correspondent
Indoor air quality concerns more than just the fumes and smoke in the house. Dampness and mould pose health risks too, especially for people living with asthma. Researchers warn that people's living habits and the new energy efficient technology used to revamp old houses might actually give indoor damp and mould more room to rise. The need for adequate heating, ventilation and home maintenance remains crucial for ones lung health.

The presence of several types of mould can lead to breathing problems in people living with asthma, as well as increase the likelihood of developing the condition, British researchers reaffirmed recently in the Journal of Allergy and Clinical Immunology.

"Most people may not be aware that moulds are abundant in our outdoor and indoor environments. Our exposure to different amounts and types of mould can be affected by weather conditions, the amount of spores in the air, and whether we have damp in our homes. If you have a house or flat that suffers from dampness, you are more likely to have more mould," Richard Sharpe, researcher at the University of Exeter Medical School’s European Centre for Environment and Human Health, told Citizen News Service.

Specific moulds

"With 1 in 3 persons suffering from allergies in industrialised countries, there has been an increasing focus on indoor air quality," Sharpe continues. "A robust body of evidence now suggests that rates of allergic and respiratory diseases are linked to poor indoor housing conditions. We looked at specific types of mould to examine which types were most likely to cause breathing problems and worsen asthma symptoms."

The researchers critically reviewed the findings from various studies done in the United States, the United Kingdom, Sweden, Taiwan, Columbia, Australia, Canada and China. The team identified links between a number of different types of fungi, (including Aspergillus and the antibiotic-producing Penicillium) and breathing problems in those with asthma. The study highlights the need for homes to have adequate heating, ventilation and home maintenance – all factors that will help to reduce the presence of mould and its effects on asthma symptoms.

Harmful effects

A typical home houses around 10 varieties of mould. "We have found the strongest evidence yet of their potentially harmful effects, with higher levels of some of these moulds presenting a breathing hazard to people living with asthma, worsening their symptoms significantly," Sharpe says. "It also looks that mould may help to trigger the development of asthma – although research in this area is still in its infancy.”

Homes with poor heating and ventilation are especially prone to high humidity, often making them a haven for mould. Dampness is one of the major factors affecting the growth of mould inside homes - a problem which has been on the rise as ageing houses are sealed and retrofitted to make them more energy efficient. The researchers are aiming to understand how new building practices intended to reduce energy use – such as improved insulation, changing heating systems, draft proofing homes and energy efficiency – can affect occupants’ health.

“Our research has highlighted the need for housing providers, residents and healthcare professionals to work together to assess the impact of housing interventions," co-author and Senior Research Fellow, Dr Nick Osborne, states. "We need to make sure that increasing the energy efficiency of people’s homes does not increase their exposure to damp and mould, and potentially damage their health.”

Humid habits

Little is known on how people's living habits can contribute to indoor air quality and ultimately affect their health. "The extent to which a home is heated and ventilated greatly affects the prevalence of damp and is largely controlled by the habits of its occupants," Sharpe explains. "Yet the way people live in their homes varies hugely. For example, some people dry their washing on indoor racks, some shower with the window closed, and many keep their windows and doors closed as much as possible in winter."

"All of these behaviours can increase the humidity and dampness in a home," he adds. "Poorer families, in particular, are less likely to maintain adequate ventilation through the winter months, often failing to heat the whole building. Collecting data through questionnaires with residents and the detailed sampling of homes, we are hoping to shed light on the complex mix of factors that affect indoor dampness (that has a bearing on respiratory problems) and communicate best practices to reduce the presence of mould. "

Babs Verblackt, Citizen News Service - CNS 
8 October 2014