Monitoring of Toxic Methyl Bromide Failed
15 May
2009
Port Marlborough’s Monitoring of Toxic Methyl Bromide Failed.
Methyl bromide fumigation leakage at Picton two weeks ago has shown that the on site monitoring systems employed by Port Marlborough are unable to protect the public, according to the Soil & Health Association of NZ.
Soil & Health are concerned that further fumigations may take place before adequate safeguards are in place and are calling for Shakespeare Bay log fumigations to be stopped ahead of Marlborough District Council reviewing its Air Plan and Port Marlborough making publicly available a Fumigation Code of Practice that has the same features as that for Port Nelson.
Referring to the inadvertent release of toxic methyl bromide gas from under tarpaulins on May 1 by fumigation company Genera, when covers came away during fumigation of logs, the Marlborough Express newspaper reported yesterday that Port Marlborough’s Chief Executive had said that early release of the gas could have put workers at risk and was unacceptable, but that on site monitoring showed methyl bromide had not exceeded one part per million.
“A release of hundreds of kilos of gas not breaching the one part per million criteria, simply shows what Soil & Health has said all along; that monitoring is effectively useless unless based on expert air dispersion modelling that considers topographical and meteorological conditions, including breezes, calms, and inversions,” said Soil & Health spokesperson Steffan Browning.
“While criteria of one part per million may seem laudable, if the monitoring system employed by the Port actually worked for detecting risk, then the one part per million threshold would have been breached. It is ludicrous to suggest the leaks and other crude releases of methyl bromide gas during recent fumigations have all remained less than one part per million beyond the Port boundary.”
“Modelling would show where the gas would go under a range of situations. Only then, depending on weather and residual gas dispersal management following a gas recapture process, appropriate placement of and type of monitor, could Port Marlborough assume gas dispersion was meeting even their prescribed safety standards.”
“Port Marlborough and its contracted monitoring agency had just seven monitors in place around the Shakespeare Bay site during the recent fumigation. Positively, two of the monitors photographed by Soil & Health were near public vantage points but without computer dispersion modelling, and with many hundreds of metres of boundary, the placements totally fail to relate to where the gas may be going.”
“In a letter to the Guardians of the Sounds chairperson Peter Beech, an air quality scientist has previously stated that, “…The consensus among all air quality practitioners around the world is that computer dispersion modeling is the first step in assessing the possible exposure to an air contaminant. …Trying to monitor an invisible plume of methyl bromide with a hand held worker exposure meter is like trying to catch a mosquito with a bird net, completely worthless.”
“Without computer dispersal modeling supporting a robust Resource Management Air Plan, fumigation in Marlborough is light years behind in safety than neighbouring Nelson,” said Mr Browning.
“By not knowing where the toxic gas goes or its concentrations along the way, Port Marlborough, Marlborough District Council, Genera, and log exporter Zindia are all gambling with community and worker safety. They are also choosing to ignore the very serious effects on climate change by the release of tonnes of one of the worst ozone depleting gases.”
“Externalising the true cost of forestry onto the rest of the community, locally or globally is not acceptable. If the timber industry wants to export commodity logs to markets that insist on methyl bromide fumigation, then they should build fumigation facilities that can recapture the toxic used gas. Alternatively develop other markets or higher value products.”
“Soil & Health has campaigned against methyl bromide fumigation for many years and will continue to campaign for a clean green Aotearoa New Zealand and against methyl bromide use. Soil & Health has a vision of an Organic 2020.”
ends