Particulate matter 2.5 concentrations, 2006-2021

Particulate matter (PM) comprises solid and liquid particles in the air. PM2.5 particles have a diameter less than 2.5 micrometres. They can be inhaled and deposited deep in the lungs where air-gas exchange occurs.

Short- and long-term exposure to PM2.5, even at low levels, is linked to respiratory and cardiovascular disease, and increased risk of premature death, especially in vulnerable people (the young, the elderly, and people with respiratory illness). Emerging evidence points to possible links with cognitive function, neuro-development, and diabetes.

In New Zealand, most PM2.5 in the air results from combustion (for example, burning wood for home heating), and to a lesser extent, from reactions in the atmosphere (secondary PM), and from naturally occurring sea salt.

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.