Hazardous air pollutants
Chemicals
There are many potentially hazardous air pollutants (HAPs). They include dioxins and polychlorinated biphenyls (PCBs), benzene, polycyclic aromatic hydrocarbons (PAH), 1,3-butadiene, acetaldehyde, xylene, toluene, styrene, formaldehyde, benzo(a)pyrene, mercury, chromium, arsenic and lead.
Sources
Hazardous air pollutants are released from activities like burning waste (including plastics, medical and hazardous waste), landfill fires, burning wood or coal for home heating, motor vehicles, smoking, spray painting, using solvent base paints, fibreglass manufacture, application of agrichemicals, industries such as synthetic rubber manufacture, oil refining, adhesive manufacture, and particle board mills.
Effects on health
Hazardous air pollutants can adversely affect human health in a number of ways including skin, throat and eye irritation, headaches, nerve and organ damage, and increased risk of cancers and premature death. This usually happens when the pollutants are breathed in over long periods of time as hazardous air pollutants can accumulate in our bodies. However some hazardous air pollutants can have a short-term effect. The Ambient Air Quality Guidelines (2002) include more information on the health effects of each pollutant.
Groups that are most sensitive to hazardous air pollutants
Humans and some animals.
Guideline values to protect health
The New Zealand ambient air quality guidelines are health-based guideline values that aim to protect people's health and well-being. They are generally designed to protect those who are most susceptible to experiencing health effects when a particular contaminant is inhaled. The New Zealand guideline values for nine priority hazardous air pollutants are:
| Contaminant | Guideline value | Averaging Time |
|---|---|---|
| Benzene (year 2002) | 10 µg/m3 | Annual |
| Benzene (year 2010) | 3.6 µg/m3 | Annual |
| 1,3-Butadiene | 2.4 µg/m3 | Annual |
| Formaldehyde | 100 µg/m3 | 30 minutes |
| Acetaldehyde | 30 µg/m3 | Annual |
| Benzo(a)pyrene | 0.0003 µg/m3 | Annual |
| Mercury (inorganic) | 0.33 µg/m3 | Annual |
| Mercury (organic) | 0.13 µg/m3 | Annual |
| Chromium VI | 0.0011 µg/m3 | Annual |
| Chromium metal and chromium III | 0.11 µg/m3 | Annual |
| Arsenic (inorganic) | 0.0055 µg/m3 | Annual |
| Aresine | 0.05 µg/m3 | Annual |
| Lead | 0.2 µg/m3 | 3 month moving average |
Readers intending to reference these guidelines are strongly recommended to refer to the Ambient Air Quality Guidelines (2002) for further information on the application and intended use of the guideline values.
Usual levels in New Zealand
Research and monitoring shows that hazardous air pollutant levels in New Zealand are generally low. However, there are some places where levels do pose a risk to human health. Further monitoring is needed to fully understand the effect of hazardous air pollutants on New Zealanders and our environment. For more information on levels check out the the state of the environment report 2007 (benzene), health effects of CO, NO2, SO2, ozone, benzene and benzo(a)pyrene in New Zealand (2003), and air quality technical report 13 (2000), which considers the health effects of 11 hazardous air pollutants in New Zealand. Your local regional or unitary council may also have further information.
Areas where hazardous air pollutants may affect health
Hazardous air pollutants may cause localised problems around discharges where concentrations are high, and also from domestic fires and vehicles in larger urban areas.
![Agrichemical spraying in an orchard. [photo]](/issues/air/images/chemspray.jpg)
Hazardous air pollutants released into the air during spraying of agrichemicals in orchards can be hazardous if the spraying is not done correctly.
Last updated:6 December 2011
