8 April 2019
The Ministry of Health contracts Emission Impossible Ltd (EIL) to provide specialist air quality support. As part of this contract EIL have conducted a study on the health impacts of unsealed road dust to provide to the National Dusty Roads Working Group (on which the Ministry is a member).
The study utilised continuously monitored particulate matter less than 10 micrometres (PM10) data collected from near an unsealed road in Northland by Northland Regional Council in partnership with Far North District Council. This is the first time in New Zealand that an unsealed road has been monitored for PM10 for a full year.
The study provides an assessment of the annual average PM10 exposure directly attributable to an unsealed road in New Zealand. This in turn, enabled an assessment of the health effects of this PM10 exposure from all unsealed roads in Northland.
Utilising an exposure-response relationship model from the 2012 updated Health and Air Pollution in New Zealand study, chronic health impacts, and costs, of exposure to PM10 from unsealed roads in Northland were assessed.
This assessment considered premature mortality, cardiovascular hospital admissions, respiratory hospital admissions and restricted activity days. This assessment found inter alia 0.6 (0.3-0.9) cases of premature mortality per year due to unsealed road dust. The total cost of adverse effects assessed was $2.7 million ($1.2-3.8 million, $2017) per year.
Datasets
The attached spreadsheets contain the data and calculations used to assess PM10 exposure and associated health effects. These are provided so that other researchers can undertake their own assessments.
Northland road dust exposure - 31 Jan 2019
This dataset contains validated PM10 monitoring data, collected near Pipiwai Road in Northland, for a full year ending 1 June 2018.
This spreadsheet also includes traffic data for this monitoring period and modelling to estimate the PM10 exposure directly attributable to unsealed roads.
Northland road dust health costs - 31 Jan 2019
This dataset contains baseline data from the HAPINZ model for Northland.
The spreadsheet also includes traffic and population estimates used to estimate the people potentially exposed to PM10 from unsealed roads.
This spreadsheet also includes an estimate of economic costs associated with adverse health effects updated to $2017.
It then models the exposure-response relationships in HAPINZ 2012 to provide estimates of adverse health effects for people living near unsealed roads in Northland.
Also included are sensitivity analyses for key parameters (such as the disproportionate effect that air pollution may have on Maori), and an acute effects assessment for comparative purposes.