Wednesday, May 28, 2008

Overnight Shift Work Identified as "Probable Carcinogen"

The International Agency for Research on Cancer (IARC), a part of the World Health Organization has evaluated more than 900 agents since 1973, of which approximately 400 have been identified as carcinogenic or potentially carcinogenic to humans. After a thorough review of scientic evidence and expert working group with IARC has concluded that shiftwork that involves circadian disruption is probably carcinogenic to humans.


Medical research studies have found that long-term night workers have a higher risk of breast cancer than women who do not work at night. The studies show that constant light, dim light at night or simulated chronic jet lag can substantially increase tumour development. Other studies show that reducing melatonin levels at night increases the incidence or growth of tumours.


The agency noted that these study results may be explained by the disruption of the circadian system that is caused by exposure to light at night. This can alter sleep-activity patterns, suppress melatonin production and disregulate genes involved in tumour development. The noted that the most disruptive shiftwork is nightwork.


This classification will be of importance to healthcare and automotive workers among others who work midnights in our city and province.



The IARC website is an extremely useful website when it comes to identifying cancer causing agents and can be found at http://www.iarc.fr/ENG/Databases/index.php.

Tuesday, May 20, 2008

Do I have to attend an employer requested health exam

If you are receiving benefits from the Workplace Safety and Insurance Board, your employer may ask you to attend to a health examination with a doctor chosen and paid for by the employer. You are not required to attend this appointment until ordered to do so by WSIB. Although, you may wish to consider how not attending will impact on your relationship with your employer. I often advise clients that you have nothing to hide and in fact the independent medical may actually assist your claim.

If you decide however that you do not want to attend the employer requested health examination, you must tell your employer that you object to the examination. I recommend that you do this in writing and carbon copy the Board. After receiving your objection, the employer has 14 days to write and request that the WSIB order you to attend the examination.

This is not automatically done by the Board. The employer must show that the examination is necessary and it will:


  • help with your early and safe return to work

  • provide significant new information not already available in your claim file

  • help clarify any disagreements in the medical opinions of doctors,

  • help better understand the nature of your injury

The Board will not approve an independent medical examination if the employer is sending you for an opinion merely because they disagree with the current medical opinions. All medical examinations are limited to the work related injury.