Air quality monitoring in Richmond between 2013 and 2015 has identified the presence of arsenic at the Oxford St monitoring station.
Monitoring data indicates the annual average arsenic concentration for 2014 in Richmond of 19 nanograms per cubic metre of air exceeded the New Zealand Ambient Air Quality Guideline of 5.5 as an annual average).
A detailed analysis, carried out by GNS Science on behalf of the Tasman District Council, identified two sources of this arsenic – a seasonal increase from the burning of treated wood in domestic fires and occasional higher concentrations possibly linked with an industrial source in the area.
Council Environment and Planning Manager Dennis Bush-King says it is extremely disappointing to find evidence of arsenic at such levels.
“This event is a timely reminder to residents that burning treated or painted timber is not permitted under the Tasman Resource Management Plan, because burning this type of wood releases toxic substances into the air and creates toxic ash.
“People need to remain vigilant about what they put into their wood burners, as treated timber may not always have a readily identifiable ‘greenish tinge’.”
Council staff have also identified a possible industrial source, undertaken some sampling, and issued an abatement notice to prevent any future unsafe burning.
“Worksafe New Zealand has been advised and will be involved if there is any need to safeguard workers at the possible industrial sites from any associated health risks,” Dennis says.
Nelson Marlborough District Health Board public health officers are working with the council to determine any public health implications from the elevated arsenic levels.
“We will provide updates on this as soon as the information becomes available.”