Air Data

Nitrogen dioxide (NO2) is a gas that is harmful to human health, ecosystems, and plants (US EPA, 2008). It can be emitted directly into the air but is often formed as a secondary pollutant when nitric oxide (NO) emissions react with other chemicals. It also contributes to the formation of secondary particulate matter (PM) and ozone, which have their own health impacts. In New Zealand, motor vehicles are the main human-made source of nitrogen oxides (NOx), the collective term for NO2 and NO. Because nitrogen dioxide concentrations are closely associated with vehicle emissions, it can be used as a proxy for other motor-vehicle pollutants such as benzene, carbon dioxide, and carbon monoxide.
Human exposure to high nitrogen dioxide concentrations causes inflammation of the airways and respiratory problems, particularly asthma. Nitrogen dioxide causes leaf injury in plants exposed to high levels. It also contributes to forming secondary particulate matter and ozone, which have their own health impacts.
We report on observed nitrogen dioxide concentrations from 13 regional council and unitary authority monitoring sites. Council and unitary authority data are measured using regulatory-compliant monitors that can be directly compared with health guidelines.
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.

Sulphur dioxide (SO2) is a highly reactive gas formed when fuels containing sulphur, such as coal or petrochemical products (including high-sulphur ship fuel), are burned. It is also produced from industrial processes such as superphosphate fertiliser production and smelting sulphur-containing metal ores. Geothermal and volcanic gases are the main natural sources of sulphur dioxide.
When inhaled, sulphur dioxide is associated with respiratory problems such as bronchitis. It can aggravate the symptoms of asthma and chronic lung disease and cause irritation to eyes. On days with higher sulphur dioxide levels, hospital admissions for cardiac disease and mortality increase. In ecosystems, it can injure vegetation, acidify water and soil, and affect biodiversity.
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.

Black carbon is a particle, often in the PM2.5 or ultra-fine size range, which is emitted from combustion sources and is commonly known as soot. In New Zealand most black carbon is emitted from vehicles (especially diesel vehicles), burning wood and coal for home heating, and outdoor burning. Both long and short-term exposure to black carbon is linked to serious health effects, such as respiratory and cardiovascular disease, cancer, and premature death (World Health Organization (WHO), 2013).
Black carbon warms the climate globally and regionally because it is efficient at absorbing energy from sunlight. Black carbon also increases ice and snow melt when deposited on these surfaces, darkening them and lowering albedo (proportion of light that is reflected) so they absorb more solar energy (Ramanathan & Carmichael, 2008).
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.

Inhaling particulate matter (PM) containing heavy metals can cause serious health effects (World Health Organization (WHO), 2013). Airborne arsenic is linked to lung cancers (WHO, 2013), and heart, liver, kidney, and nerve damage (Caussy, 2003). Nickel and vanadium are linked to lung and nasal sinus cancers. Lead can impair cognitive function in children and affect an adult’s cardiovascular system, even at low blood levels (WHO, 2013).
Heavy metals are also toxic to other organisms, and can bioaccumulate in animals, especially in aquatic ecosystems (Rahman, Hasegawa, & Lim, 2012). We don’t know how much airborne heavy metal is deposited in New Zealand.
We report on the concentrations of arsenic, lead, and vanadium in PM10 (PM 10 micrometres or less in diameter) from 2007-16 at Henderson – Auckland which were measured using a method directly comparable to relevant guidelines. We also report on arsenic, nickel, lead, and vanadium concentrations at 5 Auckland sites from 2005–16 that were measured using a method which cannot be directly compared to relevant guidelines but provides information on concentrations.
Arsenic is emitted when burning wood treated with copper chromium arsenic preservative (eg building project offcuts). A 2012 Auckland study showed that 17 percent of households may burn such wood (Stones-Havas, 2014).
Lead is emitted from burning wood coated with lead-based paint, by removing lead-based paint from buildings without proper safety precautions, and from industrial discharges (eg at metal smelters). In New Zealand, airborne nickel and vanadium concentrations are highest near ports and are associated with combustion exhaust from ships (Davy & Trompetter, 2018). Monitoring for lead has been limited since the fall in ambient lead concentrations after New Zealand’s petrol became lead free in 1996.
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.