Deborah Read

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) plasma concentrations in residents of Paritutu, New Zealand: evidence of historical exposure.

An assessment of community exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was undertaken in Paritutu, New Zealand. The suburb lies adjacent to an agrichemical facility that produced 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), between 1962 and 1987. Soil TCDD measurements from 73 nearby addresses demonstrated a pattern of TCDD deposition consistent with an aerial plume following the prevailing local wind patterns and the agrichemical plant as the point source. Blood samples were taken from 52 volunteers having lived for three or more years in Paritutu between 1962 and 1987. Candidate selection focused primarily on individuals who were most likely to show elevated TCDD blood lipid levels when compared to age and gender stratified national average blood concentrations, and secondarily on individuals that provided additional information about specific exposure periods, potential exposures of younger age groups, and specific dietary patterns. A multipathway exposure model was used to estimate serum TCDD levels in each participant. Age and gender-specific TCDD elimination kinetics were also considered. Historical TCDD environmental concentrations were back-calculated from soil concentrations at each residence assuming TCDD releases occurred pre-dominantly between 1962 and 1975. Serum was analysed for chlorinated dibenzodioxins and dibenzofurans, and a subset was analysed for dioxin-like polychlorinated biphenyls. TCDD in serum lipid exceeded two standard deviations above national background levels for 14 participants, and 3 standard deviations for 10 participants. The highest TCDD lipid concentration was 33.3 ng/kg-lipid, or 11 times higher than the comparative 1997 national average. Elevated TCDD concentrations were observed primarily, but not exclusively, in the older study participants who had been in residence in Paritutu before 1968. The study demonstrated TCDD exposure in this community, occurring most likely through the aerial route, and most probably from fugitive emissions during manufacture.

The 2005 Wellington influenza outbreak: syndromic surveillance of Wellington Hospital Emergency Department activity may have provided early warning

Objectives: To assess whether the Wellington Emergency Department (ED) Respiratory Syndromic Surveillance System may have provided early warning of the influenza outbreak in Wellington schools during 2005, and as a result might have provided the opportunity for an earlier or more effective public health response.

The Importance of Using Public Health Impact Criteria to Develop Environmental Health Indicators: The Example of the Indoor Environment in New Zealand

Developing environmental health indicators is challenging and applying a conceptual framework and indicator selection criteria may not be sufficient to prioritise potential indicators to monitor. This study developed a new approach for prioritising potential environmental health indicators, using the example of the indoor environment for New Zealand. A three-stage process of scoping, selection, and design was implemented. A set of potential indicators (including 4 exposure indicators and 20 health indicators) were initially identified and evaluated against indicator selection criteria. The health indicators were then further prioritised according to their public health impact and assessed by the five following sub-criteria: number of people affected (based on environmental burden of disease statistics); severity of health impact; whether vulnerable populations were affected and/or large inequalities were apparent; whether the indicator related to multiple environmental exposures; and policy relevance. Eight core indicators were ultimately selected, as follows: living in crowded households, second-hand smoke exposure, maternal smoking at two weeks post-natal, asthma prevalence, asthma hospitalisations, lower respiratory tract infection hospitalisations, meningococcal disease notifications, and sudden unexpected death in infancy (SUDI). Additionally, indicators on living in damp and mouldy housing and children’s injuries in the home, were identified as potential indicators, along with attributable burden indicators. Using public health impact criteria and an environmental burden of disease approach was valuable in prioritising and selecting the most important health impacts to monitor, using robust evidence and objective criteria.

Quality of Drinking-Water and Its Relation To Gastrointestinal Disease in Children

Evidence from NZ and overseas suggests that gastrointestinal diseases transmitted by drinking-water contribute significantly to the disease burden in developed countries. However there has been no systematic or strategic research in New Zealand to examine the size of the burden of endemic gastrointestinal disease, risk factors for illness, or sources of infection. Our aim was to test the relationship between acute gastrointestinal disease and quality of drinking-water, as measured by (i) actual levels of contamination with indicator organisms and Campylobacter, (ii) transgression of microbial drinking-water standards, (iii) grading of water supply by the Ministry of Health, and (iv) traditional Maori value of the water supply. The sampling frame comprised all primary schools of more than 90 children that were on municipal water supplies. All schools on poor water quality supplies (ie >5% of routine samples contaminated with E. coli) were asked to participate and were matched by geographic location and socioeconomic status with an equal number of schools that had good water quality supplies (ie. those of Aa–Bb grade and that complied with the current New Zealand Drinking-Water Standards). A daily diary was used to gather information about water usage, selfreported gastrointestinal disease (GID) and several potential confounding factors from a cohort of 1,194 primary school-aged children over a sevenweek period, at which time the drinking-water quality at each school was monitored. Preliminary results indicate that poor quality drinking-water supplies are a significant cause of GID, relative risk of 1.35 (95% CI of 1.09–1.65; P < 0.05) and an attributable risk of 0.075. These results must be viewed with caution as only 15% of the pupils at the selected schools chose to participate in the diary study, giving rise to potentially serious selection bias although once enlisted the response rate was 85%. Selection bias was addressed by a preliminary questionnaire that sought information about exposure of 1,194 participants and 1,685 non-participants to confounding factors, which showed that similar exposures were reported by both groups for most attributes measured. However, participants reported significantly higher exposure than non-participants to animals. Conclusion. The elevated risk of GID attributed to poor quality drinking-water applies to the 11% of the population not connected to a community water supply and the 10% that are connected to d or e grade or ungraded community drinking-water supplies, with a population attributable risk of 1.4%.