Kidney cancer rates have increased over time, which is attributable to changes in medical imaging for disease detection as well as changes in the prevalence of lifestyle and behavioural risk factors [1]. Tobacco smoking is the largest well-known risk factor for kidney cancer and increases the risk of disease by 50% [2].
Known occupational risk factors
Possible occupational risk factors
Increased risks of kidney cancer were detected among groups potentially exposed to TCE, one of the few well-established occupational risk factors for kidney cancer, including metal manufacturing, several metalworking occupations, and certain transportation equipment manufacturing industries. There was also a strong elevated risk among firefighting occupations, who may be exposed to many different chemicals [5,6]. No excess risk was observed among workers in printing-related occupations or industries or among welders and flame cutters.
Workers in metal manufacturing, including metalworkers, may be exposed to TCE, which is used for metal degreasing. These workers tend to be the most heavily exposed [7]. Metal machine tool operators are among the largest occupational groups exposed to TCE [8]. Workers in metal-related occupations may also be exposed to cadmium. Groups working with minerals containing copper and iron, which showed increases risks in the ODSS, may also be exposed to arsenic [9].
TCE may be used to degrease metal parts in motor vehicle manufacturing. Cadmium batteries are used in the railroad industry as a source of emergency power and for starting engines [10].
Firefighters are exposed to potentially harmful substances and work-related circumstances including shiftwork, flame retardants, and diesel engine exhaust, and when fighting fires where they can be exposed to various mixtures of particulates, gases and fumes [11]. More recent studies [12–14] and meta-analyses [11,15–17] have generally not found consistent evidence of an increased risk of kidney cancer associated with firefighting.
Truck drivers showed increased risks of kidney cancer, which may relate to high smoking prevalence. Emerging research has also linked occupational gasoline and diesel exhaust with increased risk of kidney cancer [4].
Elevated risks of kidney cancer were also observed for several additional groups with potential exposure to TCE and PFOA. Launderers and dry cleaners, a group that may work with PFOA and TCE to remove stains, showed an increased risk of disease that was based on a relatively small number of cases. Other groups with potential exposure to TCE, including groups within textile fabricating, assembling and repair (e.g., sewing machine operators) had small or no cases of kidney cancer, or too few cases to generate precise estimates. Occupational risks for kidney cancer among baking occupations are unclear.
Certain nursing subgroups showed elevated rates of kidney cancer, but this was not consistently observed. For instance, nurses and orderlies are among the occupation groups with the largest number of workers exposed to ionizing radiation [18]. Nurses showed decreased rates of kidney cancer, but orderlies and other groups within nursing showed increased rates.
*Nursing therapy and related assisting occupations, nec, include workers who provide support in diagnostic and therapeutic procedures
Figure 1. Risk of kidney cancer diagnosis among workers employed in each industry group relative to all others, Occupational Disease Surveillance System (ODSS), 1999-2016
The hazard ratio is an estimate of the average time to diagnosis among workers in each industry/occupation group divided by that in all others during the study period. Hazard ratios above 1.00 indicate a greater risk of disease in a given group compared to all others. Estimates are adjusted for birth year and sex. The width of the 95% Confidence Interval (CI) is based on the number of cases in each group (more cases narrows the interval).
Figure 2. Risk of kidney cancer diagnosis among workers employed in each occupation group relative to all others, Occupational Disease Surveillance System (ODSS), 1999-2016
