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- Bonde, Jens Peter, et al.
(författare)
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Work at night and breast cancer - report on evidence-based options for preventive actions
- 2012
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 38:4, s. 380-390
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Tidskriftsartikel (refereegranskat)abstract
- In 2007, the International Agency for Research on Cancer classified shift work involving circadian disruption as probably carcinogenic to humans (group 2A), primarily based on experimental and epidemiologic evidence for breast cancer. In order to examine options for evidence-based preventive actions, 16 researchers in basic, epidemiological and applied sciences convened at a workshop in Copenhagen 26-27 October 2011. This paper summarizes the evidence from epidemiological and experimental studies and presents possible recommendations for prevention of the effects of night work on breast cancer. Among those studies that quantified duration of shift work, there were statistically significant elevations in risk only after about 20 years working night shift. It is unclear from these studies whether or not there is a modest but real elevated risk for shorter durations. Hence, restriction of the total number of years working night shift could be one future preventive recommendation for shift workers. The diurnal secretion of melatonin by the pineal gland with peak in secretory activity during the night is a good biochemical marker of the circadian rhythm. Disruption of the diurnal melatonin secretion pattern can be diminished by restricting the number of consecutive night shifts. Reddish light and reduced light intensity during work at night could potentially help diminish the inhibitory activity of light with strong intensity on the melatonin secretion, but further mechanistic insight is needed before definite recommendations can be made. Earlier or more intensive mammography screening among female night shift worker is not recommended because the harm benefit ratio in this age group may not be beneficial. Preventive effects of melatonin supplementation on breast cancer risk have not been clearly documented, but may be a promising avenue if a lack of side effects can be shown even after long-term ingestion. Women with previous or current breast cancer should be advised not to work night shifts because of strong experimental evidence demonstrating accelerated tumor growth by suppression of melatonin secretion. Work during the night is widespread worldwide. To provide additional evidence-based recommendations on prevention of diseases related to night shift work, large studies on the impact of various shift schedules and type of light on circadian rhythms need to be conducted in real work environments.
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| 2. |
- Pearce, Neil E, et al.
(författare)
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IARC Monographs : 40 Years of Evaluating Carcinogenic Hazards to Humans
- 2015
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Ingår i: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 123:6, s. 507-514
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recently the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also the approach used to perform these evaluations. Some critics have claimed that IARC Working Groups' failures to recognize study weaknesses and biases of Working Group members have led to inappropriate classification of a number of agents as carcinogenic to humans.OBJECTIVES: The authors of this paper are scientists from various disciplines relevant to the identification and hazard evaluation of human carcinogens. We have examined here criticisms of the IARC classification process to determine the validity of these concerns. We review the history of IARC evaluations and describe how the IARC evaluations are performed.DISCUSSION: We conclude that these recent criticisms are unconvincing. The procedures employed by IARC to assemble Working Groups of scientists from the various discipline and the techniques followed to review the literature and perform hazard assessment of various agents provide a balanced evaluation and an appropriate indication of the weight of the evidence. Some disagreement by individual scientists to some evaluations is not evidence of process failure. The review process has been modified over time and will undoubtedly be altered in the future to improve the process. Any process can in theory be improved, and we would support continued review and improvement of the IARC processes. This does not mean, however, that the current procedures are flawed.CONCLUSIONS: The IARC Monographs have made, and continue to make, major contributions to the scientific underpinning for societal actions to improve the public's health.
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| 3. |
- Settimi Dionisi, Laura
(författare)
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Cancer risks and immunological effects in agriculture
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In general, farmers and agricultural workers are characterized by relatively low mortality rates when considering all causes of death and deaths due to all types of cancer. However, several studies have shown that this occupational category tend to be at increased risks of developing the following forms of malignancies: leukaemia, lymphomas, multiple myeloma, and cancers of the skin, lip, prostate, stomach, brain, and connective tissue. Although the reported excesses have not been consistent in different studies, they nevertheless suggest that agricultural exposures, especially pesticides, contribute to cancer aetiology through different mechanisms of action. It has been hypothesised that immunotoxic effects may play a role, since most of the malignancies found to be increased in workers employed in agriculture are also elevated in patients suffering from innnunodeficiencies. The present studies were conducted to ascertain whether agricultural activities and exposures influence the risk of developing cancer, and to evaluate the innnunological effects of phenoxy herbicides as possibly important for the aetiology of lymphomas.Different types of cancer were considered in relation to farming in two case-control studies, focused one on men and the other on women. A decreased risk of postmenopausal breast cancer (odds ratio [OR] 0.4) and an excess of skin melanoma (OR 2.7) and bladder cancer (OR 2.7) were observed in the women. The main finding in the men was an excess of prostate cancer (OR 1.5). Further analyses showed that this malignancy was associated with exposure to chlorinated compounds (OR 2.5), and, more specifically, to DDT (OR 2.1) and dicofol and tetradifon (OR 2.8).Mortality in selected groups of farmers and their relatives was investigated in two cohort studies. Farmers and their wives showed reduced mortality from all causes and all cancers although there was a tendency towards increased risk of leukaemia, particularly among wives of pesticide users (standardised mortality ratio [SMR] 2.4). Adult sons and daughters of green-house owners exhibited increased mortality from all types of cancer (SMR 1.9).A study was also performed to compare pre- and post-exposure values of selected immunological parameters in a group of ten farmers exposed to phenoxy herbicides. The most notable fmdings were reduced levels of the following: circulating natural killer (NK) cells (-38%), NK cytotoxic activity (-53%), and lymphocyte response to mitogenic stimulation (-50%).
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