DURBAN - Toxicology experts hired by EnviroServ have said in a report that they could not rule out that exposure to the fumes hanging over the Upper Highway region posed no health risk. However they doubted the fumes caused cancer.
The Infotox team, led by chemical toxicology and human risk assessment specialist, Dr Willie van Niekerk, was appointed by EnviroServ in October to conduct a human health risk assessment. The report was handed to the company last month.
This was after an escalation in the number and intensity of community complaints about the smell with people saying “toxic fumes” from the landfill were making them sick.
“Cancer risks were calculated and it was concluded that cumulative cancer risks associated with all carcinogenic substances were not significant and did not reflect reasons for concern,” the report said.
But, in a submission to the Department of Environmental Affairs, the civil group, Upper Highway Air (UHA) has questioned the credibility of the Infotox report.
They allege it was a watered-down version of the initial report compiled by the same firm in March.
One inconsistency the group highlighted was the claim that the risk of adverse health effects associated with exposure to hydrogen sulphide (H2S) in communities living around the landfill was not high because the concentration was low.
UHA said this contradicted the initial report.
There Van Niekerk said reactions to hydrogen sulfide could result in respiratory effects, nasal symptoms, sore throats, cough and dyspnoea.
By way of example the report said that upper respiratory tract bleeding was the predominant complaint in a study of workers temporarily living in an oil field camp that intermittently experienced short term or low concentration exposure.
More symptoms were also similar to those reported by residents in the Upper Highway area which included headaches, wheezing, shortness of breath and nasal congestion.
EnviroServ’s occupational health practitioner Dr Carlos de Nobrega’s claim that none of the landfill’s employees suffered any health symptoms related to fumes has also come under attack with the UHA saying there was no reliable evidence to prove this.
UHA’s own air quality specialist, Dr Lisa Ramsay from WSP Parsons Brinckerhoff, also highlighted discrepancies between the WSP results and those of the 15 hydrocarbon samples collected by Infotox.
“The maximum benzene concentration measured on site (890 μg/m3) by Infotox was at the brine tank. This concentration falls below our fenceline measurement of 3 667 μg/m3,” she said in one of the examples.
Ramsay said further on site measurements were required since the current data collected by Infotox might be an underestimate of the real impact of the landfill.
“We are confident that the source of the volatile organic compounds we measured was the Enviroserv landfill site. The intensity of the hydrocarbon odour increased as we moved closer to the Enviroserv fenceline. One does not expect off-site measurements to be higher than measurements at the source, as is the case here,” she explained.
The UHA has accused EnviroServ of misrepresenting the implications of dumping 16 000 tons of gypsum and 46 000 tons of aluminium then deliberately omitting some of the information such as the hydrogen sulfide reading for at least five months last year.
EnviroServ’s chief executive Dean Thompson said he would not be able to comment on the Infotox report as the matter was before the Durban High Court as part of the UHA’s bid to get the landfill permanently shut down.
Of the remedial action on site he said they were working according to the odour and gas management plan submitted to the DEA.
“The engineering design for the progressive capping design of the front face of the landfill has been approved and construction has started. We are awaiting the design approval from the gas extraction and treatment system and as soon as this approval has been received, this installation will commence. The estimated completion date is still August,” he said.