Occupational Health Clinic for Ontario Workers, 1999

1.) Background

The Occupational Health Clinic for Ontario Workers (OHCOW) opened its office in Windsor in January of 1992. OHCOW has clinics in Hamilton, Sudbury and Toronto. The Windsor clinic has been assigned to provide medical, hygiene, and ergonomic services to other communities in southwestern Ontario, including Sarnia.

Starting in 1993, in conjunction with the Sarnia and District Labour Council, arrangements were made for the clinic to come to Sarnia approximately once a month. Ergonomic and hygiene services were made available as required.

In August, 1994 the first patient who had previously worked at Fiberglas in Sarnia, asked for an appointment. This patient had been diagnosed with a benign brain tumour. He believed that there was a possible link between his illness and his exposures at the Fiberglas.

Fiberglas opened in 1948 and closed May 31st 1991. It employed over 25,000 production workers, mostly male. The plant was owned by Owens Corning.

The clinic staff was not well acquainted with the actual working conditions and potential exposures that might have occurred at the Sarnia Fiberglas plant. It was reported by the workers, however, that the working conditions were particularly poor. It was reported that the plant was very dusty.

Within a few months another former Fiberglas worker made an appointment to see one of our nurses. This individual had been diagnosed with cancer of the hypopharynx. He had worked for over 35 years as a production worker as well as a maintenance worker/millwright. During the course of his work life he had been exposed to fiberglass, asbestos, machining fluids, and other hazardous substances. He also had compiled a list of over 25 former Fiberglas workers that had either died of or had been diagnosed with cancer.

With his permission, we contacted the Communication, Energy, and Paperworkers (CEP) Union, Local 914 President, Ken Glassco. The union had previously represented the Fiberglas workers. (Ken Glassco is also the President of the Sarnia & District Labour Council.) Through our discussions with Mr. Glassco, we learned that McMaster University had conducted an epidemiological study in the mid 1980s involving the Fiberglas workers employed between 1955 - 1977. The study reported a statistically significant two-fold excess of lung cancer among the plant workers.

The CEP agreed that there might be work-related health problems among the former Fiberglas workers and offered to help the clinic investigate whether some of them might need the services of OHCOW.

CEP also prepared an extensive mailing which covered over 300 former Fiberglas workers and their families. A short questionnaire regarding possible health problems was enclosed which focused primarily on respiratory problems and cancer.

This report is a summary of the OHCOW investigation. Based on our findings, the clinic wishes to make a number of specific recommendations for CEP's consideration.

2. What is Fiberglass?

The formal name of fibreglass, according to the International Agency for the Research of Cancer (IARC), is Glass Fibres.

There are two groups of glass fibres: glasswool (formed by drawing, centrifuging or blowing molten glass, it is comprised of cylindrical fibres of relatively short length) and glass filament (formed by continuously drawn, or extruded from, molten glass).

Sands and some kinds of oxides such as aluminium, magnesium, calcium, and sodium are major raw materials in the production of glass fibres.

The most common resins used in production are phenol-formaldehyde and melamine-formaldehyde.

3.) Fibreglass Production Process

Fine-powder sand and other materials are heated until they melt and then refined to form molten glass. The molten glass then is drawn, centrifuged or blown to extrude a fibre of a given size. The spray of binders, which contain resin, urea, formaldehyde, lubricants and asphalt, prevent fibre abrasion and act as bonding agents. Curing, packing or fabricating fibres are later stages in the production process.

A variety of potential workplace hazards exist beyond fibreglass, in the production process, particularly at all material transfer points; debagging stations, the forming stations and fabrication areas. These hazards include noise, heat, dusts and fumes of different types (such as asbestos, poly-cyclic aromatic hydrocarbons (PAHs), arsenic, coal-tar, bitumen, quartz, chromium, benzene-soluble organic, formaldehyde, strong acids...) which may cause resulting health effects, such as hearing loss, heat stress, skin problems, respiratory problems, and cancers.

PLEASE SEE TABLE 1

4. Industrial Hygiene Review

Our industrial hygienist talked with a number of former Fiberglas workers to determine potential exposures to toxic substances. He also reviewed a number of occupational health and safety, toxicological and medical databases, including MEDLINE, NIOSHTIC and TOXLINE. He found that in the literature the following substances were present in fibreglass plants:

IARC has classified arsenic, asbestos, oil mist, sulfuric acid and silica as Group 1 human carcinogens. PAHs and formaldehyde are classified as Group 2A, which connotes "probably carcinogenic to humans."

There are eight substances that are recognized as human lung carcinogens among the compounds that former Fiberglas employees were potentially exposed to in the course of their work.

5.) Investigations of Lung Cancer in the Sarnia Area

5.a) McMaster University Health Study

In 1987 Harry Shannon of McMaster University Health Science Centre published a study of the Sarnia Fiberglas workers. The McMaster group conducted a mortality study which involved 2557 former Fiberglas employees who worked at the Sarnia facility from 1955 to 1977.

Shannon reported that among the in-plant workers, whereas other cancers occurred at a rate that would be expected in the normal population, there was a statistically significant two fold excess of lung cancer. The Standard Mortality Ratio (SMR) was 199.

The researchers noted that the excess lung cancer was too large to be attributable to cigarette smoking which is the usual confounder in lung cancer cases. Siemiatycki et al. analyzed 25 separate occupations to determine whether excess lung cancer was due to confounding from cigarette smoke. He concluded that a high relative risk from lung cancer in these occupational settings (greater than 1.40) is unlikely due to smoking.

There was, however, difficulty with aspects of the study's report findings. Shannon reported that the SMRs by length of exposure and time since first exposure were not consistent with an occupational exposure. Shannon, however, notes two points made by Dr. Doll in 1985.

"The first is that very short-term workers may have unusually high mortality. Of the cases among plant workers, four occurred in men with less than 1 year exposure - yet were grouped in the "less than 5 year category".

"On the other two in this category, one died only 2 years after starting work and at an unusually young age (28) for this disease. Omission of these men would produce more consistent results, but it is unclear how comparable the different categories would then be. In addition, we excluded men with less than 90 days' employment, whereas, Doll's definition of "very short term" is less than 1 month.

"The second point is that in similar analyses of other cohorts do not always show the "expected" pattern, yet they may not be considered to show that the presumed hazard is not a carcinogen, if there is a considerable amount of strong evidence to the contrary."

The McMaster study was presented to an international symposium on synthetic mineral fibres in Copenhagen in 1986 chaired by Dr. R. Doll. He reported that the excess lung cancer among fibreglass-exposed workers was not large, but that even a 10% to 20% increase was a matter of concern. He concluded that the fibres play a role in excess lung cancer.

The World Health Organization (WHO) issued a Summary Report on the International Symposium - Man-made Mineral Fibres in the Working Environment. Commenting on the epidemiological evidence, WHO states:

"...Only crude dose-response relationships were apparent from the studies carried out. This problem is unfortunate but does not negate the likelihood of a causal relationship. First of all, the mere duration of employment may not necessarily be a valid indicator of the cumulated individual exposure because of the changing exposures over the observation period. Further, early fibre exposures may have a higher biological significance than fibres more recently inhaled and retained in the lungs for a short time only. Finally, estimates of past exposures may be inaccurate or even erroneous. "

5.b) Asbestos-Associated Cancers in the Ontario Refinery and Petrochemical Sector

The Ontario Ministry of Labour physician, Murray Finkelstein, published a study on asbestos-related lung cancer among Sarnia Refinery and Petrochemical Sector employees. The purpose of the study was to determine whether there was excess lung cancer among the area refinery workers.

Dr. Finkelstein reports that Lambton county has the highest rates of pleural mesothelioma in Ontario and ranks fourth for the rate of peritoneal mesothelioma in men. Mesothelioma is a "marker" disease for other asbestos-related diseases, such as lung cancer and asbestosis.

He also cites a finding that fiberglass workers in Lambton county had over a four-fold excess of lung cancer that was statistically significant.

PLEASE SEE TABLE 2

5.c Conclusion

A review of the potential exposures in the fibreglass production process shows that there at least eight substances that are recognized lung carcinogens. If exposures were not properly controlled, then it could be predicted that there would be an excess cancer risk among these workers.

The McMaster epidemiological study of the Sarnia Fiberglas plant workers did, in fact, find a statistically significant two-fold lung cancer excess. The authors, however, were concerned about the lack of a clear dose/response trend. Dr. Doll and the World Health Organization both concluded, however, that there are reasons why this lack of a dose-response pattern may not be apparent. Both further conclude that this problem does not "negate the likelihood of a causal relationship."

Dr. Finkelstein's findings of a statistically significant four-fold lung cancer excess among Sarnia area fibreglass workers further confirms the excess cancer risk among this group of workers.

6.) Literature Review

6.a) Infante's Review

Dr. Peter Infante produced a scientific review of the potential carcinogenicity of fibreglass, titled Fibrous Glass and Cancer. He conducted a thorough review of the data from animal studies and epidemiologic studies. This review focused on whether fibreglass should be listed as a carcinogen in the Seventh Annual Report on Carcinogens (ARC) prepared by the National Toxicology Program (NTP) and mandated by the U.S. Congress.

He reported that:

"...At least 13 studies demonstrate biologically plausible and statistically significant increases in the incidence of lung cancer and mesothelioma in rats and hamsters exposed to glass wool by various routes using standard scientific methods.... Eleven inhalation studies of glass wool in rats, hamsters, guinea pigs and baboons reported no statistically significant increase in cancer; these inhalation studies, however, were determined to be inadequate and inconclusive due to limitations in study methodology or incomplete/uninterpretable presentation of results."

Dr. Infante also summarized a number of epidemiologic studies of lung cancer among workers exposed to glass wool fibers.

PLEASE SEE TABLE 3

Infante et al summarize their review of the epidemiological literature and conclude that the excess lung cancer, found in these studies, was not confounded by smoking, chance or selection bias and therefore, "it seems scientifically plausible that a case can be made that the elevated risk is related to synthetic fiber exposure."

Dr Infante concludes that "fibrous glass materials are carcinogenic" and "on a fibre-per-fibre basis, glass fibers may be as potent or even more potent than asbestos."

6.b) Summary of Literature:

The following table summarizes the most significant literature searched on fibreglass and lung cancer.

(Safety concern is another topic and will not be included here.)

PLEASE SEE TABLE 4

7.) Individual Cases

Between 1994 and 1996, the OHCOW clinic saw 13 former Sarnia Fiberglas employees. Six of the thirteen had been diagnosed with cancer.

PLEASE SEE TABLE 5

8.) Risk Mapping

To assist the clinic staff in determining the potential exposure profile of former Fiberglas workers, we employed a technique called Risk Mapping. It helped to give us a clearer view of the different operations of the plant. In the absence of any actual exposure data, we participated in a process organized by the Sarnia & District Labour and the Sarnia Occupational Safety and Health Group (SOSH). The two organizations hired a Lambton Community College student, to work with former Fiberglas employees to identify the different areas of the plant, as well as the specific hazards. The following plant departments were identified:

8.a) Batch House

This was the location where the raw materials were dumped into mixers and blended. The workers believed that this was a A "very dusty area" and one of the worst areas to work. There was high exposure to many of the ingredients, particularly silica, soda ash and dolomite. Just outside the batch house were large storage tanks containing:

• formaldehyde
• sulfuric acid
• 40% urea
• phenol
• ammonia

8.b) Binder room, Melting Tanks and Forehearths

On the second level, melting tanks melted the batch and the forehearths carried the batch to the wool department located on the ground level. In the Binder room the fibres were melted together to form sheets. The chemicals that were used to bind the fibres into sheets included:

• ammonia
• formaldehyde
• phenol
• oil
• sulfuric acid
• urea

The workers considered this an area with "high" exposures.

8.c) Wool Department

From the forehearths, glass is melted in large ovens and the liquid is poured into channels, and then pushed through the bushings and into the spinners. Tiny holes in the spinners removed the small pieces of glass which came out as "fluff." The "fluff" fell into chains on a conveyor belt forming wool chains, which was sent through a slitting section where it was cut and sent to the packing area.

There was a tar pit located below the packaging area which was called the Asphalt Application Area. Here the tar was heated and applied to the paper backing to stick to the length of the wool before it was cut. Workers reported that there was a very fine dust created by the wool slitting section of the work line. Conditions here were considered very hot, extremely dusty and picky from the fibers.

Workers in this area had to clean out the exhaust ventilation and the stacks every 4-5 weeks. The maintenance workers had to remove asbestos from the oven doors and recoat them.

8.d) Maintenance: Mechanical, Electrical, Instrumental

These workers were employed through the operation and often reported "high" exposures.

8.e) Yard Crew

Workers assigned to this part of the operation participated in cleanouts and outdoor/indoor loading and unloading. Chemicals such as paint, varsol, oil, and cleaning agents were stored in this area in large barrels.

8.f) Aerocor Mat Plant & Pulforming

The wool from the S-3 and S-4 oven was cured in this department. The material from the Binder room was pumped into this area. Wool was cut and packed. The workers reported "heavy" binder room fumes of ammonia, formaldehyde, and phenol.

8.g.) Moulded Pipe

In Department #8 uncured wool from S-5 was put into the moulded pipe press by hand. The press lid would close and high heat was forced through the fiber to cure the binder and form the pipe. This area was very hot and very smoky and some phenol, formaldehyde and ammonia. Trim area was very dusty and some smoke. Press area was probably the worst area in the plant, or next only to the batch house.

There were three large presses which made pipe from high temperature clay. The three foot halves of pipe were dipped in clay and baked in the ovens. The pipe was then edged, trimmed, painted and packed. The workers reported a very fine dust from the trimming combined with very strong paint fumes.

6.h) Acoustical Tile & Sono Core

This operation opened in the 1980s. The paper face of the tile was glued to plastic backing and placed in an oven. It was later cut into squares. The tile edges were trimmed and packed. The workers reported the ventilation was good with limited exposures.

9.a) Meetings and Mailing

Three meetings were organized by Ken Glassco and the CEP to inform the former Fiberglas workers of the clinic's efforts to investigate possible occupational disease among this group of workers. The union organized a mailing accompanied by a questionnaire prepared by OHCOW staff which would assist in documenting possible health problems. The clinic hired a computer consultant to program a database using Lotus Approach that could maintain the records from this mailing.

The union mailed approximately 150 letters and received 44 responses. This represents a 30% response rate. Of the people that returned the questionnaires to the union, 30% indicated they had developed cancer. Another 20 % indicated they had developed breathing problems, including one case of lung scarring.

SEE TABLE 6

9.b) Conclusions

Dr. Infante's review of the cancer potential of fibreglass is the most current, as well as, thorough summary of the known scientific evidence. He concludes that "fibrous glass materials are carcinogenic" and "on a fibre-per-fibre basis, glass fibers may be as potent or even more potent than asbestos."

The epidemiological evidence further supports Dr. Infante's contention that fibreglass production poses a cancer risk for the workers employed in the process.

The OHCOW investigation, which included seeing patients, developing a questionnaire, maintaining a database, and developing a Risk Map, confirms the general pattern that is evident throughout the scientific literature. The workers own accounts affirm that the workplace was extremely "dusty" with many potential exposures to hazardous substances, including carcinogens.

We believe there is a "probable connection" for the workers with respiratory cancers and their exposures while employed at Fibreglas. The cases with non-respiratory cancer and other health problems need to be reviewed on a case by case basis.

10.) Recommendations

OHCOW-Windsor believes there are work-related cancers and possibly other respiratory diseases among the former Fiberglas workers. The McMaster study specifically found a statistically significant two-fold excess of lung cancer. The Literature Review found a consistent pattern of excess lung cancer in both human and animal studies. The Fiberglas workers were also exposed to a myriad of other hazardous substances that may have contributed to other cancers and diseases.

We believe the CEP should consider the following recommendations:

• The union needs to assign an advocate to assist with the lung cancer compensation cases. OHCOW would be available to assist with medical or hygiene assessments.
• Representation should be made with the WCB to try to expedite the claims, particularly those involving lung cancer.
• A public meeting should be held to make our report public and inform the former Fiberglas workers of the union's plans.
• There are still fibreglass plants in operation which are represented by CEP and other unions. This report should be shared with them so that they might be appraised about the possible cancer risk. Also an assessment should be conducted regarding the current occupational health and safety conditions in these plants with the goal of prevention.