Science Centres: Energy

Monitoring toxic hydrocarbons in Auckland's air

Auckland smog.

Toxic volatile hydrocarbons (known as VOCs) are emitted by vehicles and pose health risks for people breathing urban air.

The Ministry for the Environment has identified four VOCs in petrol – benzene; 1,3-butadiene; formaldehyde; and acetaldehyde – as 'priority organic contaminants' for monitoring.

The Auckland Regional Council has contracted NIWA to conduct the first long-term continuous monitoring of benzene and 1,3-butadiene in this country. This involves operating a new automated gas chromatography system (Synspec GC955), owned by the ARC, at the Khyber Pass Road air quality monitoring site. Khyber Pass Road is a traffic hot spot with over 30 000 vehicles passing the site each working day.

The data collected so far have not been analysed in any detail. However, initial readings suggest that levels of benzene and 1,3-butadiene at Khyber Pass Road are likely to be high by world standards. Over the next year, we hope to see levels of these VOCs drop as better quality fuel comes on-stream thanks to New Zealand Refining’s upgrade at Marsden Point and new government fuel specifications (from 1 January 2006).