Environmental factors are responsible for more than 3000 premature deaths a year in New Zealand, and a large number of other ongoing health issues. Many of these could potentially be avoided.

New research published by the World Health Organisation (WHO) shows that many of the health issues caused from the physical, chemical and biological factors in a person's environment are actually avoidable.

Globally, the report states that almost one in four deaths were linked to unhealthy environments and that environmental risks now contribute to more than 100 of the world's most dangerous diseases, killing 12.6 million people a year.

In 2012 in New Zealand, 3137 deaths, 11 per cent, were attributable to environmental factors.


The biggest change in the WHO data over the past 10 years has been the increase in the number of deaths from non-communicable diseases including strokes, cancers and heart disease - which make up two-thirds of the global total.

Cancer is the leading cause of premature death, with one-third of people living in industrialised countries expected to develop the disease. The WHO estimates that 19 per cent of all cancers are attributable to environmental factors, and therefore many cases are potentially preventable. Unsurprisingly, the report identifies smoking as the greatest risk factor for developing lung cancer. Other than smoking, though, lung cancer deaths were associated with indoor and outdoor air pollution sources, including the burning of wood for heat and car exhaust fumes.

The report also links 35 per cent of heart disease cases to environmental factors. Clearly our surroundings have a significant impact on our health, and not just the outdoors as 18 per cent of heart disease cases were linked directly to the environmental causes inside the home. With us spending more than 90 per cent of our time indoors, the effect of our indoor environment on our health is important.

To illustrate how simple changes can reduce the risk of health issues, consider how we heat our homes. Some common forms of heating - unflued gas heaters in particular - cause elevated levels of humidity and condensation, creating moisture as a byproduct of the gas combustion. The condensation in turn can lead to potentially harmful mould growth which can cause respiratory issues such as infections, asthma and allergies. A Housing, Heating and Health Study in New Zealand found that installing a heat pump in place of a gas heater resulted in a significant reduction in indoor condensation and mould growth, which then reduced the associated health risks.

A larger proportion of New Zealand rental accommodation uses unflued gas heating as the main heating source compared to owner-occupied properties. Despite representing only a third of the homes in New Zealand, rental properties house approximately half of New Zealand's under-5s and 34 per cent of these homes have shown some level of subjective dampness.

According to the WHO report, the young and elderly are most susceptible to the impacts of environmental factors on their health, in particular respiratory problems caused by indoor factors. A relatively simple change in the way we heat our homes could potentially have a significant health impact for those identified as being most at risk.

Despite fairing relatively well in the report when compared with some other countries, New Zealand still has plenty of room for improvement. Locally, the 2012 Health and Air Pollution study showed that harmful emissions from vehicles caused 256 premature deaths a year, resulting in $934 million annually in social costs covering hospital admissions and restricted activity days. The data shows there are potentially significant gains by reducing the risk factors in our environments, inside and out.

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