Lead levels in air
Why we monitor lead levels in air
Motor vehicle emissions used to be a major source of lead in Hamilton. In the mid-1980s steps were put in place by the New Zealand Government to reduce the amount of lead in fuels. Lead was later removed from fuels in 1996. This has eliminated a major source of lead in the environment. The removal of lead from fuels indicates that reductions in lead are likely in all areas of the Waikato Region.
Removal of lead-based paint from houses can still cause lead poisoning. Although it’s not used for exterior house paint in New Zealand anymore, lead-based paint can still be found on some older houses (especially those built before the late 1970s). Young children can swallow harmful amounts of lead by eating, chewing or putting lead-contaminated paint flakes or dust in their mouths. Pets are also susceptible to lead poisoning.
Waikato Regional Council measured ambient air lead levels in Hamilton. Hamilton was suspected to be at risk from lead because of high levels of traffic.
Lead was measured in Hamilton from 1983 to 2001. Results show a large drop in the amount of lead in Hamilton’s air. From August 1993 to August 2001, lead levels were consistently below the Ministry for the Environment guideline value (0.2 µg/m3 as a three-monthly average), indicating that lead is no longer of concern in Hamilton.
Why lead levels in air are important
Lead is a heavy metal that can affect people’s:
- nervous system – for example, causing headaches, disturbed sleep, depression, difficulty concentrating
- immune system – decreasing the body’s ability to fight infection
- blood pressure – causing it to increase.
Children are more at risk from lead poisoning than adults. Lead is dangerous to children because it can cause brain damage, affect their growth, and cause learning and behavioural problems. Young children can swallow harmful amounts of lead by eating, chewing or putting lead contaminated paint flakes or dust in their mouths.
More detail on this indicator, including how and where Waikato Regional Council collects this information, is available in the Technical Information page.
Contact at Waikato Regional Council
Air quality scientist - Science and Strategy Directorate
Last updated 20 June 2008