3 Health Effects Studies for New Zealand
Epidemiological studies of the relationships between concentrations of particles and health in New Zealand are limited to two studies carried out in Christchurch. The first study was a time-series design that considered the impact of both PM10 concentrations and temperature on mortality (Hales et al, 1999). Results indicated an increase in both all cause mortality and respiratory mortality associated with a one-day lag in PM10 concentrations measured at the St Albans monitoring site in central Christchurch. The size of the effect, 1% (0.5-2.2%) for all cause mortality was reasonably consistent with similar studies carried out in other countries (e.g. Dockery et al, 1994). An association between respiratory mortality and PM10 concentrations of 4% (1.5-5.9%) per 10 µgm-3 increase in daily PM10 concentrations was also recorded. Unlike some overseas studies, no relationship between deaths from cardiovascular disease and PM10 concentrations was observed.
In addition to the Hales et al(1999) mortality study, a study of the relationship between hospital admissions and particle pollution was carried out in Christchurch by McGowan et al (2002). Results indicated a 3.37% increase in respiratory hospital admissions and a 1.26% rise in cardiac admissions for each interquartile rise in PM10 concentrations (interquartile value 14.8 µgm-3). The size of the effect was generally consistent with overseas studies (e.g. Schwartz and Morris, 1995).
