Environmental health and your heart
Environmental risks such as extreme heat, bushfire smoke, noise and chemical pollution can strain the heart and lungs, increasing cardiovascular disease risk, particularly for vulnerable communities.
Protecting the health of our environment is increasingly recognised as part of protecting the health of our hearts. Environmental factors are linked to millions of cardiovascular deaths worldwide each year, with air pollution alone recognised as a major modifiable risk factor for heart disease. This is the second part of a series exploring the connection between the environment and our vital organs.
While air pollution has become the most widely recognised environmental threat to the heart — and was the focus of the first article in this series — it is far from the only one.
New international guidance from the European Society of Cardiology (ESC), American College of Cardiology (ACC), American Heart Association (AHA) and World Heart Federation (WHF) confirms that a wider set of environmental stressors are now recognised as important contributors to cardiovascular disease, alongside traditional risk factors such as smoking, high blood pressure, diabetes and high cholesterol.
These stressors include extreme heat, bushfire smoke, noise pollution, chemical pollution and climate-related disasters.
How does the environment affect heart and lung health?
Our heart and lungs work together to supply oxygen throughout the body.
Environmental stressors of all kinds can increase the workload on both organs through several biological pathways, including inflammation, oxidative stress, damage to blood vessels, and changes to the nervous system that regulates heart rate and blood pressure.
These changes can increase the risk of heart attack, stroke, heart failure, cardiac arrhythmias (such as atrial fibrillation) and high blood pressure.
Worsening respiratory conditions place additional strain on the heart as well.
Research increasingly describes these exposures as environmental cardiovascular risk — a component of cardiovascular risk that exists in addition to the traditional risk factors we routinely manage.
In New Zealand, climate change is not just an environmental issue — it is also a cardiovascular health issue.
Protecting resilient communities and healthy environments is an important part of preventing cardiovascular disease.
Heat and extreme weather
During hot weather, the body works harder to cool itself by increasing blood flow to the skin and producing sweat.
This places extra strain on the heart and may increase the risk of dehydration, low blood pressure, heat exhaustion and cardiovascular events — particularly in older adults and people taking medicines such as diuretics.
Bushfire smoke and other episodes of extreme weather add to this burden, compounding the effects of poor air quality already covered in part one of this series with the physical stress of heat, disrupted routines and reduced access to care during climate-related disasters.
Who is most vulnerable?
Environmental health risks do not affect everyone equally. People at greatest risk include:
- People living with heart disease or stroke
- Older adults
- People with chronic respiratory disease
- People with diabetes or multiple long-term conditions
- Māori, Pacific peoples and communities experiencing health inequities
- People with limited access to cooling, housing or healthcare during extreme weather events