Remediation Technologies for Arsenic Contamination

¶ … Remediation technologies for Arsenic Contamination at Deloro Mine, Eastern Ontario

The tiny eastern Ontario village of Deloro has been the victim of arsenic poisoning for generations. More disturbing, the environment ministry was aware of the poisoning for more than a decade before they had decided to take action. This literature will review the specific details of the contamination of the Deloro Mine site in Eastern Ontario. In addition, it will cover literature regarding specifically arsenic contamination and the effects of this poisoning.

The Poisoning of Deloro:

The provincial government had known for more than a decade that the people of Deloro had been breathing arsenic-laden air and living with arsenic-poisoned soil, according to McAndrew in his 1999 article.

However, on June 10th, 1999 the approximately 175 residents learned the truth, during a community meeting organized by the ministry to inform the residents about the cleanup efforts that would be conducted at the abandoned Deloro gold mine and smelter.

It was revealed that tests conducted on a private property, outside of the mine, more than a decade earlier, showed arsenic contamination in the soil an average of 30 times higher than then acceptable levels, with the maximum approximately 240 times the acceptable level. Although residents had known for years that there was a problem at the mine site itself, they were unaware that it had actually extended to their village as well.

It was believed that the arsenic in the village came from the smoke stacks of the refinery that closed in 1961. In addition, McAndrew's 1999 article surmises that recent contamination occurred due to dust blown by the wind from the piles of mine wastes (tailings) sitting on the site.

The tailings piles were eventually covered by rock in order to prevent the dust from being blown further into town, which is just west of the mine property boundary.

Yanagisawa's ministry's finding put forth that Deloro residents were in "no more significant health risks than other Ontario citizens."

However, clearly there was issues as ministry workers and even a construction crew that extended a natural-gas pipeline had to wear containment suits, while the crew that installed the original pipeline two-to-three years ago wore normal work clothing.

However, residents are not comfortable with the ministry reassurances, especially given the ministry's past withholding of evidence, notes Yanagisawa. In fact, the ministry's commitment to spend $1.66 million for short-term maintenance of drinking water, reduction of radon gas, removal of pockets of contaminated soil, and the fencing of the mine site, did little to ease their fears. Although the government workers completed the $800,000 chain link fence, it was too little, too late.

Yanagisawa further cites sources that uncovered the fact that the mine site was supposed to be fenced and remediated in the 1950s. This concurs with McAndrew's 1999 findings that the ministry ignored the arsenic laden tailings to drift into town.

In addition, Yanagisawa goes beyond McAndrews' 1999 report and discusses the effects on Moira Lake. In the summer of 1999, the residents of Moira Lake were warned by the Ministry of Environment officials not to drink the water or eat the fish from the lake.

She notes, "Arsenic has been found in sediment about 45 kilometres downstream, where the Moira empties into the Bay of Quinte after passing through Tweed and Belleville."

McAndrew's 2000 article notes that residents were further given information to protect themselves against contamination, seemingly in contrast to their assurances that all was well in the village of Deloro, as they noted in Yanagisawa.

One resident was specifically told to wear gloves when she wanted to garden in the contaminated soil around her home, as a precaution.

Again, furthering the doubt residents had in government assurances.

The 350-hectare site of the closed mine and refinery has long since been considered to be the most contaminated piece of land in Ontario. Ministry officials have admitted to this much, and have estimated that it could take up to $30 million to remediate the area to stop the piles of toxic waste from leaking into the Moira River. McAndrew's 2000 article notes that the ministry took control of the Deloro Mine site in 1979, when the owners reported they were not able to afford the clean-up operations

Arsenic Contamination and Poisoning:

Arsenic is a by-product of the mining industry. It is a known cancer-causing agent, and can be ingested through food that has been grown in contaminated soil, and can also be absorbed through the skin. If small amounts are absorbed over a period of time, it can result in chronic arsenic poisoning. This poisoning can produce: nausea, headaches, changes in skin colorization, scaling of the skin, anorexia, and white lines across the fingernails. If large amounts of arsenic are consumed, this can lead to vomiting and renal failure, and even death, as noted by McAndrew, in 1999.

Franzblau and Lilis go beyond McAndrews' 1999 description of arsenic poisoning. They show chronic arsenic poisoning as resulting in nonmalignant cutaneous changes, as McAndrews notes, including hyperpigmentation and hyperkeratoses, as well as renal toxicity; however, it also has been known to cause skin cancers, 'Blackfoot disease' - a disease of arsenic-induced peripheral vascular insufficiency that leads to gangrene, hepatic toxicity, peripheral neuropathy, and hermatopoietic toxicity.

Franzblau and Lilith state that much of the classic description of arsenic poisoning comes from suicidal or homicidal ingestion. In addition to McAndrews' 1999 description of symptoms, ingestion can also lead to abdominal cramps, and diarrhea that may be bloody. The researchers further specify that ingestion of water containing less than 1,000 ?g/l of arsenic, over several years, can lead to poisoning.

Myoung-Jin and Yejin concur with McAndrew's 1999 findings that much arsenic contamination comes from mine tailings. These researchers used the Jingok mine in Bongwha, Korea for their study regarding the vertical distribution of arsenic and heavy metals, through leeching into the ground and ground water. Nearby paddy fields were found to have an extremely high concentration of arsenic, and as testing was conducted at increased distances from the mine site, the levels fell dramatically.