Whole body vibration risk to pregnant workers
An increasing number of women are choosing to work in industries where whole-body vibration exposure is common, but still, very little is known about risks of such exposure during pregnancy. And in a country like Australia, there is no exposure standard.
Swedish researchers, noted that some occupational exposures have been inconsistently associated with pregnancy complications, but that exposure to whole-body vibrations (WBV) had been largely overlooked even though it has been associated with adverse birth outcomes. Consequently, they studied the Fetal Air Pollution Exposure cohort, formed by merging multiple Swedish, national registers containing information on occupation during pregnancy and diagnosis codes. It includes all working women who gave birth between 1994 and 2014 (over 1 million). They derived WBV exposure from a job-exposure matrix, and divided into exposure categories. The aim was to assess whether occupational WBV exposure during pregnancy is associated with pregnancy complications.
They found that among women working full time there were increased risks of all pregnancy complications in the highest exposure group (≥0.5 m/s2), compared with the lowest. Exposed women (mainly truck drivers, forklift and heavy machine operators) working full time had an increased risk of both preeclampsia, gestational hypertension and gestational diabetes. However, there were no clear associations for part-time workers. The researchers said the results are alarming, as the associations were apparent below the current exposure limit value set by the European Union. They said that women should not be exposed to WBV at/above the action limit value of 0.5 m/s2 (European directive) continuously through pregnancy. However, these results need further confirmation.
In terms of policy implications, the researchers said that the results are likely to lay the foundation of future risk assessment of pregnant women exposed to whole-body vibrations. If confirmed by others, they said the results indicate that women should not be continuously exposed to whole-body vibrations throughout pregnancy, which supports development of policies for reassignment or pregnancy allowance for at least part of the pregnancy. It is concerning that despite the evidence and standards in other countries, there are NO EXPOSURE STANDARDS for vibration in Australia (see: Vibration).
Read more: Helena Skröder, et al. Occupational exposure to whole-body vibrations and pregnancy complications: a nationwide cohort study in Sweden (Full text) Occupational and Environmental Medicine Online first June 2020
IARC confirms night work cancer link
An association between night work and breast and other cancers has been confirmed after a major review by an International Agency for Research on Cancer (IARC) expert group. IARC’s 2007 ‘probably carcinogenic in humans’ Group 2A ranking was challenged in 2016 after an Oxford University study co-financed by the Health and Safety Executive (HSE) and Cancer Research UK (CRUK) concluded “night shift work, including long-term night shift work, has little or no effect on breast cancer incidence.” The paper, which attracted headlines worldwide and whose findings were welcomed by both HSE and CRUK, concluded IARC’s ranking of night work as a ‘probable’ cause of breast cancer in women “is no longer justified.” However, the paper attracted strong criticism and was dismissed as ‘bad science’ by leading work and breast cancer experts (Risks 781).
The controversy led IARC, a World Health Organisation (WHO) agency, to convene a ‘Monographs Working Group’ in June 2019. The findings of IARC’s reevaluation, published online this month, rejected the HSE/CRUK study’s conclusions. Instead, the IARC expert group again “classified night shift work as ‘probably carcinogenic to humans’ (Group 2A), on the basis of limited evidence of cancer in humans (for cancers of the breast, prostate, colon, and rectum), sufficient evidence of cancer in experimental animals, and strong mechanistic evidence in experimental animals.” However, unions have expressed concern that the doubt cast on the cancer association by the HSE/CRUK backed paper adversely affected efforts to recognise, address and compensate night-work related breast cancer.
Read more: IARC Monographs Volume 124: Night Shift Work, June 2020. Volume 124 webpage. Graveyard shift: Cancer all-clear for night work based on ‘bad science’, warn scientists, Hazards magazine, number 136, December 2016. Source: Risks 951
