By GLENN KAUTH
Today staff
Friday May 19, 2006
Fort McMurray Today — Fort McKay residents breathed a sigh of relief -- literally -- at the news Syncrude Canada’s smelly desulphurization unit is shutting down.
Treena Gladue, 30, said she had been calling Alberta Environment and Syncrude officials all week telling them to shut the unit down after her nine-year-old daughter left school early for the second time this week suffering from nausea and dizziness. “We’re getting it full impact -- almost as though the stack is coming in your face,” she said of the smell.
Thomas Mintenko, 13, said the smell in Fort McKay School became unbearable early Wednesday afternoon, forcing some students to move to another classroom. Several teachers, he pointed out, complained of dizziness, while one girl had trouble standing up.
Alberta Environment’s pollution guideline for sulphur dioxide is 172 parts per billion, a point at which health problems may occur. Alberta Environment officials did record values of 350 parts per billion at a field site near Syncrude. Still, they say the higher reading was recorded just once over a one-minute period. Concerns only arise, they say, if the reading averages more than 172 parts per billion over a one-hour period. In residential areas, readings have hovered between 25 and 50 parts per billion.
http://www.fortmcmurraytoday.com/story.php?id=231735SULFUR DIOXIDE
CAS: 7446-09-5; Chemical formula: SO2
OSHA's former limit for sulfur dioxide (SO2) was 5 ppm as an 8-hour TWA. The Agency proposed to revise this limit to 2 ppm as an 8-hour TWA and to supplement this limit with a 15-minute STEL of 5 ppm. Although NIOSH recommends a limit of 0.5 ppm for sulfur dioxide, NIOSH did concur (Ex. 8-47, Table N1) with the proposed limits. The ACGIH has a TLV-TWA of 2 ppm and a TLV-STEL of 5 ppm. In the final rule, OSHA is establishing a 2-ppm 8-hour TWA and a 5-ppm 15-minute STEL for SO2. Sulfur dioxide is a colorless, nonflammable gas or liquid with a suffocating odor.
OSHA has studied the effects of occupational exposure to SO2 for several years. The Agency's 5-ppm limit for this substance was established in 1971 on the basis of the 1968 ACGIH TLV-TWA. In 1975, OSHA proposed to revise this limit downward to 2 ppm and held public hearings to gather information on industrial exposures to SO2. In response to shifting priorities within the Agency, OSHA did not promulgate a final standard at that time. The following discussion summarizes the record evidence relevant to SO2 both from the earlier (1975-1976) record and from the record of the present rulemaking.
Workplace exposure to sulfur dioxide causes both acute and chronic effects. The chronic effects of exposure include permanent pulmonary impairment, which is caused by repeated episodes of bronchoconstriction. A number of human and animal studies demonstrate this effect (Skalpe 1964/Ex. 1-438; Smith, Peters, Reading, and Castle 1977/Ex. 1-805; Archer and Gillam 1978/Ex. 1-711; Ministry of Health (Canada) 1976/Ex. 1-1208; Lewis, Campbell, and Vaughan 1969, as cited in ACGIH 1986/Ex. 1-3, p. 542).
Kehoe, Machle, Kitzmiller, and LeBlanc (1932/Ex. 1-339) studied two groups of male refrigeration workers with long-term (average of four years) exposures to average SO2 concentrations of 20 to 30 ppm, with a range of exposures from 10 to 70 ppm. These workers were believed to have been exposed prior to 1927 to SO2 levels considerably higher and averaging from 80 to 100 ppm. This study showed that SO2 exposure caused an increased incidence of nasopharyngitis, shortness of breath on exertion (dyspnea), and chronic fatigue (Kehoe, Machle, Kitzmiller, and LeBlanc 1932/Ex. 1-339).
In a study of Norwegian paperpulp mill workers, Skalpe (1964/Ex. 1-438) reported that average SO2 concentrations were believed to range from 2 to 36 ppm. Results showed a significantly higher frequency of respiratory disease symptoms, including coughing, expectoration, and dyspnea, among workers less than 50 years of age (i.e., those with the shortest exposure). Workers older than 50, however, did not display symptomatology different from that of controls.
More recently, Smith, Peters, Reading, and Castle (1977/Ex. 1-805) studied a group of smelter workers exposed, on average, to less than 2 ppm SO2 but concurrently exposed to respirable particulate at levels generally less than 2 mg/m3. These workers showed a decrement in forced vital capacity (FVC) and forced expiratory volume (FEV1) of 4.8 percent when compared with controls. These authors concluded that workers exposed to SO2 levels above 1 ppm had an accelerated loss of pulmonary function. This study has been criticized on the grounds that the control population itself may have been exposed to respiratory toxins and that other contaminants, such as iron sulfites, may have contributed to the pulmonary decrement seen in these smelter workers. On average, 60 percent more of the workers exposed to greater than 1 ppm SO2 reported symptoms of chronic cough than did workers who were exposed to SO2 at a concentration below 1 ppm. The prevalence of chronic sputum production was elevated for workers who had never smoked and who were exposed above 1 ppm.
http://www.cdc.gov/niosh/pel88/7446-09.htmlMost of these numbers are based on an 8 hour work day and have conditions when working 12 hour shifts. So how about 24/7. Well politicans doen't have to consume this, so move on folks.
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