PM2.5 concentrations, 2008–17

PM2.5 is made up of solid and liquid particles in the air with a diameter of less than 2.5 micrometres. In New Zealand, most PM2.5 in the air results from combustion (burning wood for home heating, motor-vehicle exhaust), and to a lesser extent, particles formed from reactions in the atmosphere (secondary PM) and naturally occurring sea salt.
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.
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.