Lung Cancer - Gold Miners


Primary cancer of the trachea, bronchus or lung is accepted as an occupational disease under s.2(1) and s.15 of the Workplace Safety and Insurance Act as characteristic of gold mining in Ontario.


The following sets out categories of persuasive evidence to establish work-relatedness. In assessing entitlement, the decision-maker weighs all the work and non-work factors and determines the individual merits of the case.

Condition Necessary evidence
The worker has worked in Ontario gold mine.
Substantiated occupational history.
The gold miner has been diagnosed with primary cancer of the trachea, bronchus or lung.
Medical evidence establishing the presence of primary cancer of the trachea, bronchus or lung.
  Persuasive evidence
A biologically plausible latency period is present.
Latency can vary with intensity and type of exposure. Usually it is biologically plausible that the disease occurs
- 15 years after first employment in a "dusty occupation"*
- 5 years between first employment in mines with radon progeny and the diagnosis of the disease.

The gold miner has during the dustiest years of gold mining.


Evidence of "dusty gold mining"** experience in Ontario prior to December 31, 1945.


Evidence of "dusty gold mining" experience in Ontario in mines.

Sufficient and consistent evidence of occupational exposure must be present.

To satisfy this condition the gold miner has,

1.) a chest x-ray rating of 4 or more as rated by the Ontario WSIB chest x-ray classification system and weighted dust exposure index of 60 or more. Weighted dust exposure is the sum of years worked in "dusty gold mining" in Ontario

  • pre 1936 x 4 
  • from 1936 to 1944 x 3
  • from 1945 to 1954 x 2
  • after 1954 x 1.


2) a chest x-ray rating of 4 or more as rated by the Ontario WSIB chest x-ray classification system and was first employed in "dusty gold mining" in Ontario before attaining age of 30.


3) worked in mines which were dusty and had significant arsenic levels.


The duration of mining such mines which sufficient exposure depends on arsenic levels in the mines. The most current scientific information is used to assess whether the exposure to arsenic is to establish work-relatedness.


4) worked in mines which had significant levels of radon progeny.


The policy on lung cancer and uranium mining (see 23-02-03, Lung Cancer among Workers in Uranium Mining Industry) and the Ontario Miners Study is consulted to determine whether the exposure is sufficient to establish work-relatedness.


5) the equivalent of 5 years of "dusty gold mining" and was first employed in an Ontario gold mine before attaining 30 years of age, if no arsenic or radon exposure is present


6) the equivalent of 10 years of "dusty gold mining" if no arsenic radon exposure is present.

The above guidelines identify persuasive evidence which would indicate that the conditions for work-relatedness are met. All decisions are made in accordance with the real merits and justice of the case, and all available evidence of work and non-work factors is considered to make a determination of work-relatedness in each individual case.

*"dusty occupation" and

**"Dusty gold mining" is defined by the Ontario WSIB coding system which follows.

Dust exposure defined by occupation codes (based on WSIB codes)
11 Full time in dust exposure - mill
12 "   "   "   "   "   - other surface
13 "   "   "   "   "   - shaft sinking
14 "   "   "   "   "   - other underground
15 "   "   "   "   "   - surface and underground
16 "   "   "   "   "   - open pit
21 Part time in dust exposure - mill (including mill in open pit)
22 "   "   "   "   "   - other surface
25 "   "   "   "   "   - surface and underground
26 "   "   "   "   "   - open pit
97 Dust exposure, specifics unknown


For all allowed claims, past and future, considered under the WSIB policy on lung cancer among goldminers (either Minute No. 3, January 8, 1988, Page 5216 or Minute #5, August 29, 1991, Page 5471), eligibility for entitlement and benefits shall be retroactive to the date of accident or to the date of the worker's death in the case of survivors' benefits, and paid in accordance with the provisions of the Workers' Compensation Act or Workplace Safety and Insurance Act in effect at that time and thereafter. There is no restriction to entitlement to benefits based on whether the worker, spouse or dependants are or were alive as of a specific date.

In disease claims, the date of accident is the date of diagnosis or the date of the first medical report of related symptoms, whichever is the earlier.

Document History

This document replaces 04-04-08.


Legislative Authority

Workplace Safety and Insurance Act, 1997, as amended

Sections 2(1), 15, 119(1)


Board of Directors
#8(XX), June 10, 2004, Page 6620