Particulate air pollution and hospital admissions in Christchurch, New Zealand.

AIMS: Winter air pollution in Christchurch is dominated by particulate matter from solid fuel domestic heating. The aim of the study was to explore the relationship between particulate air pollution and admissions to hospital with cardio-respiratory illnesses. METHODS: Particulate air pollution statistics (PM10) were obtained from the Canterbury Regional Council monitoring station in the city. The New Zealand Health Information Service provided data on admissions to the Princess Margaret and Christchurch Hospitals for the period June 1988 through December 1998 for both adults and children with cardiac and respiratory disorders. The relationship between PM10 and admissions was explored using a time series analysis approach controlling for weather variables. Missing values were interpolated from carbon monoxide data for the same time period, as carbon monoxide and PM10 were highly correlated. RESULTS: There was a significant association between PM10 levels and cardio-respiratory admissions. For all age groups combined there was a 3.37% increase in respiratory admissions for each interquartile rise in PM10 (interquartile value 14.8 mcg/m3). There was also a 1.26% rise in cardiac admissions for each interquartile rise in PM10. There was no relationship between PM10 and admissions for appendicitis, the control condition selected. CONCLUSIONS: In keeping with overseas studies, there is evidence in Christchurch of a relationship between ambient particulate levels and admissions with cardiac and respiratory illnesses. The size of the effect is consistent with overseas data, with the greatest impact for respiratory disorders. IMPLICATIONS: These results indicate that measures to control ambient particulate levels have the potential to reduce hospital admissions for cardio-respiratory illnesses.

Structural and functional changes of the gastric mucosa in rats with portal hypertension.

Structural and functional changes of the gastric mucosa were studied in rats made portal hypertensive by partially ligating the portal vein. Studies were carried out at either 3 or 12 days after ligation or sham operation. At 3 days, structural changes were greater than at 12 days, the major effects being vascular congestion in the lamina propria, muscularis mucosa, submucosa, and submucosal oedema. Transmission electron microscopy showed only a mild hyperplasia in the muscularis mucosa. Gastric blood flow appeared to decrease at 3 days post-ligation compared to sham-operated control rats, but was significantly increased by 12 days after ligation (P less than 0.01). Cardiac output also appeared to increase in the portal hypertensive rats by 12 days post-ligation but this was not statistically significant. Portal venous inflow was significantly increased by 12 days (P less than 0.05) but after correction for collateral circulation liver blood flow had returned to normal values by 12 days post-ligation.