Occupational risk in health care and research

Healthy worker hire and survivor effects in a cohort of medical radiation workers

BACKGROUND

The healthy worker effect may distort the association between exposure and health effects in workers. However, few studies have investigated both the healthy worker hire and survival effects simultaneously, and they are limited to mortality studies in male workers.

METHODS

We utilized a data set comprising South Korean diagnostic medical radiation workers registered in the National Dose Registry between 1996 and 2011, and merged it with mortality and cancer incidence data. Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) were computed for comparison with the general population. To account for time-varying confounders influenced by prior occupational radiation exposure, we applied g-estimation using structural nested accelerated failure time models and compared the outcomes with those from Weibull regression.

RESULTS

A total of 1831 deaths and 3759 first primary cancer cases were identified among 93 918 workers. Both male (SMR = 0.44; 95% CI: 0.42, 0.46) and female workers (SMR = 0.53; 95% CI: 0.46, 0.60) showed lower mortality rates compared with national rates. In the SIR analysis, male workers exhibited reduced risks of solid cancer whereas female workers had increased risks. The g-estimation-derived hazard ratios (HRs) from radiation exposure exceeded those from Weibull regression estimates for all-cause death (HR = 2.55; 95% CI: 1.97, 3.23) and all-cancer incidence (HR = 1.96; 95% CI: 1.52, 2.55) in male workers whereas female workers showed the opposite results.

CONCLUSIONS

Comprehensive consideration of the healthy worker effect by sex is essential for estimating the unbiased impact of occupational exposure on health outcomes, notably in studies focusing on male mortality.

Global disease burden and trends of leukemia attributable to occupational risk from 1990 to 2019: An observational trend study

Background

Leukemia caused by occupational risk is a problem that needs more attention and remains to be solved urgently, especially for acute lymphoid leukemia (ALL), acute myeloid leukemia (AML), and chronic lymphoid leukemia (CLL). However, there is a paucity of literature on this issue. We aimed to assess the global burden and trends of leukemia attributable to occupational risk from 1990 to 2019.

Methods

This observational trend study was based on the Global Burden of Disease (GBD) 2019 database, the global deaths, and disability-adjusted life years (DALYs), which were calculated to quantify the changing trend of leukemia attributable to occupational risk, were analyzed by age, year, geographical location, and socio-demographic index (SDI), and the corresponding estimated annual percentage change (EAPC) values were calculated.

Results

Global age-standardized DALYs and death rates of leukemia attributable to occupational risk presented significantly decline trends with EAPC [-0.38% (95% CI: -0.58 to -0.18%) for DALYs and -0.30% (95% CI: -0.45 to -0.146%) for death]. However, it was significantly increased in people aged 65-69 years [0.42% (95% CI: 0.30-0.55%) for DALYs and 0.38% (95% CI: 0.26-0.51%) for death]. At the same time, the age-standardized DALYs and death rates of ALL, AML, and CLL were presented a significantly increased trend with EAPCs [0.78% (95% CI: 0.65-0.91%), 0.87% (95% CI: 0.81-0.93%), and 0.66% (95% CI: 0.51-0.81%) for DALYs, respectively, and 0.75% (95% CI: 0.68-0.82%), 0.96% (95% CI: 0.91-1.01%), and 0.55% (95% CI: 0.43-0.68%) for death], respectively. The ALL, AML, and CLL were shown an upward trend in almost all age groups.

Conclusion

We observed a substantial reduction in leukemia due to occupational risks between 1990 and 2019. However, the people aged 65-69 years and burdens of ALL, AML, and CLL had a significantly increased trend in almost all age groups. Thus, there remains an urgent need to accelerate efforts to reduce leukemia attributable to occupational risk-related death burden in this population and specific causes.

The Carcinogenic Effects of Formaldehyde Occupational Exposure: A Systematic Review

BACKGROUND

Formaldehyde, classified as a carcinogen in 2004, as of today is widely used in many work activities. From its classification, further studies were performed to evaluate its carcinogenicity. The aim of the systematic review is to update the evidence on occupational exposure to formaldehyde and cancer onset.

METHODS

The review, in accordance with the PRISMA statement, includes articles in English reporting original results of studies conducted on workers exposed to formaldehyde, considering all types of cancer, published from 1 January 2000 to 30 July 2021 and selected from the Pubmed and Scopus databases. The studies' quality was assessed by the Newcastle-Ottawa Scale.

RESULTS

A total of 21 articles were included, conducted in different European, American, and Asian countries. The most investigated occupational areas are those characterized by a deliberate use of formaldehyde. Some studies evaluated all types of cancer, whereas others focused on specific sites such as thyroid and respiratory, lymphohematopoietic, or central nervous systems. The results showed weak associations with lung cancer, nasopharyngeal cancer, leukemia, and non-Hodgkin's lymphoma.

CONCLUSIONS

The results demonstrate the need for further original studies carried out on representative samples of workers exposed to measured levels of FA. These studies should be designed to reduce the bias due to co-exposure to other carcinogens.

Chemical risk in hospital settings: Overview on monitoring strategies and international regulatory aspects

Chemical risk in hospital settings is a growing concern that health professionals and supervisory authorities must deal with daily. Exposure to chemical risk is quite different depending on the hospital department involved and might origin from multiple sources, such as the use of sterilizing agents, disinfectants, detergents, solvents, heavy metals, dangerous drugs, and anesthetic gases. Improving prevention procedures and constantly monitoring the presence and level of potentially toxic substances, both in workers (biological monitoring) and in working environments (environmental monitoring), might significantly reduce the risk of exposure and contaminations. The purpose of this article is to present an overview on this subject, which includes the current international regulations, the chemical pollutants to which medical and paramedical personnel are mainly exposed, and the strategies developed to improve safety conditions for all healthcare workers.

Exposure to Occupational Hazards among Health Care Workers in Low- and Middle-Income Countries: A Scoping Review

Health care workers are exposed to numerous workplace hazards. The implementation of safety measures in high-income countries has largely mitigated these risks. However, in many low- and middle- income countries (LMICs), resources to institute safety measures are lacking, increasing the risk of occupational exposures to these hazards. The aim of this scoping review is to map and synthesize the available research on occupational hazards among health care workers in LMICs, identify research gaps and inform policy. Searches for relevant articles were conducted in five electronic databases using a broad range of search terms. The inclusion criteria were: quantitative observational or experimental studies which examined exposure to one or more occupational hazards among health care workers in a LMCI; and the article was published in English in a peer-reviewed journal. A total of 99 studies met the inclusion criteria, and data were extracted from these studies. Large proportions of health care workers in LMICs were exposed to biological hazards (bloodborne pathogens, tuberculosis), psychosocial hazards (workplace violence, burnout, job dissatisfaction), ergonomic hazards (musculoskeletal complaints), and chemical hazards (exposure to latex and antineoplastic drugs). The implementation of risk reduction strategies was suboptimal. The majority of the literature was on biological hazards (48%), and research on other hazards was limited in comparison. Occupational safety needs to become a priority public health issue to protect health care workers in LMICs. More research is needed to understand the magnitude of the problem in these countries.

Reliability and Validity of an Adapted Questionnaire Assessing Occupational Exposures to Hazardous Chemicals among Health Care Workers in Bhutan

BACKGROUND

Collection of reliable and valid occupational history data is of utmost importance to assess work-related exposures and their health effects. Few standardized questionnaires are available for the collection of occupational history data in low-and-middle income countries.

OBJECTIVE

To adapt and test a validated questionnaire developed in the United States by the National Institute of Safety and Health, in order to assess occupational chemical exposures among health care workers in Bhutan.

METHODS

The questionnaire was first adapted to suit the Bhutanese context with the advice of an expert review committee. 30 health care workers then completed the questionnaire at baseline and 10-14 days later. Test-retest reliability was assessed by calculating Cohen's κ and percentage agreement.

RESULTS

The questionnaire had high test-retest reliability. Cohen's κ ranged from 0.61 to 1.00, and percentage agreement ranged from 86.7% to 100%. Further adaptations included omitting questions on chemicals not available in Bhutan.

CONCLUSION

The adapted questionnaire is appropriate for assessing occupational chemical exposures among health care workers in Bhutan.

Epidemic characteristics and related risk factors of occupational exposure for pediatric health care workers in Chinese public hospitals: a cross-sectional study

Background

Health care workers have a high risk of occupational exposure. However, the risk of occupational exposure for pediatric health care workers has not been acknowledged in previous studies. The purpose of this study was to investigate the occupational exposure rate of pediatric health care workers in Chinese public hospitals, to explore risk factors for occupational exposure, and to put forward corresponding countermeasures to reduce occupational exposure of pediatric health care workers and protect their physical and mental health.

Methods

A cross-sectional study was conducted with pediatric health care workers in 43 hospitals in 15 provinces in eastern, central, and western China between July and October 2018. With this sample, we computed the descriptive statistics of the demographic characteristics, calculated the frequency of various types of occupational exposure, and tested risk factors for occupational exposure using a chi-squared test and binary logistic regression analysis.

Results

Most respondents were nursing staff (61.1%) and workers with a low-ranking professional title (50.5%). The most common style of occupational exposure in our sample was a hazard in the work environment (62.6%). Notably, physicians were less likely to experience occupational exposure than nurses (OR = 0.320, 95% CI = 0.241, 0.426). Meanwhile, pediatric health care workers who interpreted the doctor-patient relationship as harmonious (OR = 0.304, 95% CI = 0.152, 0.607) were less likely to suffer occupational exposure.

Conclusion

Pediatric health care workers in Chinese public hospitals have a high occupational exposure risk and the risk factors are complex and diverse. The state, society, hospitals should acknowledge this issue and develop strategies to protect the physical and mental health of pediatric health care workers.

Menstrual disorders and occupational exposures among female nurses: A nationwide cross-sectional study

BACKGROUND

The regularity of menstrual cycles is one of the important indicators of female reproductive health. However, the current evidence on the association of occupational exposures and menstrual disorders is scarce.

OBJECTIVES

This study aims to elucidate the relationship between occupational hazards and menstrual characteristics in female nurses and non-nurse health care workers in China.

DESIGN

We conducted a national cross-sectional study on the reproductive health of female nurses in China.

SETTINGS

A total of 1, 300 medical institutions in 15 provincial administrative regions in China participated in the study.

PARTICIPANTS

There were 8, 904 nurses and 3, 977 non-nurse health care workers who were selected using simple random sampling method.

METHODS

All participants were administered a face-to-face standardized questionnaire, including personal socio-demographic information, occupational activities, and self-reported menstrual characteristics. Univariate and multivariate logistic regressions were used for statistical analyses.

RESULTS

The results demonstrated that 41% of nurses experienced menstrual disorders. We found handling disinfectants was the most significant risk factor for menstrual disorders (OR = 1.53, 95% CI: 1.39-1.68), followed by abnormal workload (OR = 1.28, 95% CI: 1.19-1.39), and occupation as a nurse (OR = 1.28, 95% CI: 1.18-1.40). Noise, prolonged standing or frequent heavy lifting, night work, anti-cancer drug exposure, and overtime work were moderately associated with the occurrence of menstrual disorder (OR > 1).

CONCLUSIONS

This national-wide cross-sectional study has revealed the significant association between menstrual disorders and occupational hazards among female nurses in China.

Occupational use of high-level disinfectants and fecundity among nurses

Objective This study aimed to examine the relationship between occupational use of high-level disinfectants (HLD) and fecundity among female nurses. Methods Women currently employed outside the home and trying to get pregnant (N=1739) in the Nurses' Health Study 3 cohort (2010-2014) were included in this analysis. Occupational exposure to HLD used to disinfect medical instruments and use of protective equipment (PE) was self-reported on the baseline questionnaire. Every six months thereafter women reported the duration of their ongoing pregnancy attempt. Multivariable accelerated failure time models were used to estimate time ratios (TR) and 95% confidence intervals (95% CI). Results Nurses exposed to HLD prior to and at baseline had a 26% (95% CI 8-47%) and 12% (95% CI -2-28%) longer median duration of pregnancy attempt compared to nurses who were never exposed. Among nurses exposed at baseline to HLD, use of PE attenuated associations with fecundity impairments. Specifically, women using 0, 1, and ≥2 types of PE had 18% (95% CI -7-49%), 16% (95% -3-39%), and 0% (95% -22-28%) longer median durations of pregnancy attempt compared to women who were never exposed. While the use of PE varied greatly by type (9% for respiratory protection to 69% for protective gloves), use of each PE appeared to attenuate the associations of HLD exposure with reduced fecundity. Conclusion Occupational use of HLD is associated with reduced fecundity among nurses, but use of PE appears to attenuate this risk.

Braf Mutations Initiate the Development of Rat Gliomas Induced by Postnatal Exposure to N-Ethyl-N-Nitrosourea

A single dose of N-ethyl-N-nitrosourea (ENU) during late prenatal or early postnatal development induces a high incidence of malignant schwannomas and gliomas in rats. Although T->A mutations in the transmembrane domain of the Neu (c-ErbB-2) gene are the driver mutations in ENU-induced malignant schwannomas, the molecular basis of ENU-induced gliomas remains enigmatic. We performed whole-genome sequencing of gliomas that developed in three BDIV and two BDIX rats exposed to a single dose of 80 mg ENU/kg body weight on postnatal day one. T:A->A:T and T:A->C:G mutations, which are typical for ENU-induced mutagenesis, were predominant (41% to 55% of all somatic single nucleotide mutations). T->A mutations were identified in all five rat gliomas at Braf codon 545 (V545E), which corresponds to the human BRAF V600E. Additional screening revealed that 33 gliomas in BDIV rats and 12 gliomas in BDIX rats all carried a Braf V545E mutation, whereas peritumoral brain tissue of either strain had the wild-type sequence. The gliomas were immunoreactive to BRAF V600E antibody. These results indicate that Braf mutation is a frequent early event in the development of rat gliomas caused by a single dose of ENU.

Cancer Incidence in Physicians: A Taiwan National Population-based Cohort Study

Cancer has been the leading cause of death in Taiwan since 1982. Physicians have many health-related risk factors which may contribute to cancer, such as rotating night shift, radiation, poor lifestyle, and higher exposure risk to infection and potential carcinogenic drugs. However, the cancer risk in physicians is not clear. In Taiwan's National Health Insurance Research Database, we identified 14,889 physicians as the study cohort and randomly selected 29,778 nonmedical staff patients as the comparison cohort for this national population-based cohort study. Cox proportional-hazard regression was used to compare the cancer risk between physicians and comparisons. Physician subgroups were also analyzed. Physicians had a lower all-cancer risk than did the comparisons (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.76-0.97). In the sex-based analysis, male physicians had a lower all-cancer risk than did male comparisons (HR 0.82, 95% CI 0.73-0.94); and female physicians did not (HR 1.29, 95% CI 0.88-1.91). In the cancer-type analysis, male physicians had a higher risk of prostate cancer (HR 1.72, 95% CI 1.12-2.65) and female physicians had twice the risk of breast cancer (HR 2.00, 95% CI 1.11-3.62) than did comparisons. Cancer risk was not significantly associated with physician specialties. Physicians in Taiwan had a lower all-cancer risk but higher risks for prostate and breast cancer than did the general population. These new epidemiological findings require additional study to clarify possible mechanisms.

Work schedule and physical factors in relation to fecundity in nurses

OBJECTIVES

To evaluate the association of work schedule and physical factors with fecundity.

METHODS

Women currently employed outside the home and trying to get pregnant (n=1739) in the Nurses' Health Study 3 cohort (2010-2014) were included in this analysis. Work schedule and physical labour were self-reported on the baseline questionnaire, and every 6 months thereafter the women reported the duration of their ongoing pregnancy attempt. Multivariable accelerated failure time models were used to estimate time ratios (TR) and 95% CIs.

RESULTS

Among the 1739 women (median age=33 years, 93% Caucasian) the estimated proportions of women not pregnant after 12 and 24 months were 16% and 5%, respectively. None of the various shift work patterns were associated with duration of pregnancy attempt (as a surrogate for fecundity). However, women working >40 h/week had a 20% (95% CI 7 to 35%) longer median duration of pregnancy attempt compared to women working 21-40 h/week (p-trend=0.005). Women whose work entailed heavy lifting or moving (ie, 25+ pounds) >15 times/day also had a longer median duration of pregnancy attempt (adjusted TR=1.49; 95% CI 1.20 to 1.85) compared to women who never lifted or moved heavy loads (p-trend=0.002). The association between heavy moving and lifting and duration of pregnancy attempt was more pronounced among overweight or obese women (body mass index, BMI<25: TR=1.17; 95% CI 0.88 to 1.56; BMI≥25: TR=2.03, 95% CI 1.48 to 2.79; p-interaction=0.007).

CONCLUSIONS

Working greater than 40 h per week and greater frequency of lifting or moving a heavy load were associated with reduced fecundity in a cohort of nurses planning pregnancy.

How to develop a standard operating procedure for sorting unfixed cells

Written standard operating procedures (SOPs) are an important tool to assure that recurring tasks in a laboratory are performed in a consistent manner. When the procedure covered in the SOP involves a high-risk activity such as sorting unfixed cells using a jet-in-air sorter, safety elements are critical components of the document. The details on sort sample handling, sorter set-up, validation, operation, troubleshooting, and maintenance, personal protective equipment (PPE), and operator training, outlined in the SOP are to be based on careful risk assessment of the procedure. This review provides background information on the hazards associated with sorting of unfixed cells and the process used to arrive at the appropriate combination of facility design, instrument placement, safety equipment, and practices to be followed.

Sharps injuries and job burnout: a cross-sectional study among nurses in China

The present study investigated the relationship between sharps injuries and job burnout in nurses. Sharps injury questionnaires and the Maslach Burnout Inventory (MBI) questionnaires were used to investigate and analyze job burnout among 468 nurses, of which 458 effective questionnaires were collected, for a response rate of 97.86%. A total of 292 nurses had at least one sharps injury (63.76% of the 458 nurses). The dimension scores were higher for injured nurses compared with non-injured nurses. The difference between the dimensions of emotional exhaustion and depersonalization for nurses with sharps injuries was statistically significant (P < 0.05). A rank correlation analysis showed that these two dimensions had a positive correlation with sharps injuries (r = 0.69-0.78). The prevalence of sharps injuries in nursing is associated with depersonalization, as measured by the MBI. Nursing administrators should pay more attention to clinically burned-out nurses, and provide more opportunity to nurses for training and education to reduce the prevalence of sharps injuries.

Occupational exposures among nurses and risk of spontaneous abortion

OBJECTIVE

We investigated self-reported occupational exposure to antineoplastic drugs, anesthetic gases, antiviral drugs, sterilizing agents (disinfectants), and X-rays and the risk of spontaneous abortion in US nurses.

STUDY DESIGN

Pregnancy outcome and occupational exposures were collected retrospectively from 8461 participants of the Nurses' Health Study II. Of these, 7482 were eligible for analysis using logistic regression.

RESULTS

Participants reported 6707 live births, and 775 (10%) spontaneous abortions (<20 weeks). After adjusting for age, parity, shift work, and hours worked, antineoplastic drug exposure was associated with a 2-fold increased risk of spontaneous abortion, particularly with early spontaneous abortion before the 12th week, and 3.5-fold increased risk among nulliparous women. Exposure to sterilizing agents was associated with a 2-fold increased risk of late spontaneous abortion (12-20 weeks), but not with early spontaneous abortion.

CONCLUSION

This study suggests that certain occupational exposures common to nurses are related to risks of spontaneous abortion.

Self-reported gastrointestinal and cardiovascular symptoms in female Turkish nurses

AIM

This study aimed to determine the prevalence of gastrointestinal and cardiovascular symptoms and to compare working conditions and lifestyle characteristics among nurses.

BACKGROUND

Gastrointestinal and cardiovascular disorders are important health problems in nurses. Although many epidemiologic studies have researched nurses' health problems, few have focused on their cardiovascular and gastrointestinal symptoms.

METHODS

A cross-sectional design was used with a sample of 400 nurses from a medical faculty hospital in northwestern Turkey. Data were collected using the Physical Health Questionnaire of the Standard Shift Work Index.

RESULTS

The nurses worked different shifts and provided direct patient care in four different clinical areas in the hospital. There were statistically significant differences in age, educational status, marital status, work years, weekly working hours and type of work shift among nurses in different units. The mean gastrointestinal symptoms subscale score was 17.7 [standard deviation (SD) = 3.2] and the mean cardiovascular symptoms subscale score was 14.4 (SD = 3.7). Compared with results in similar studies, the nurses' gastrointestinal and cardiovascular symptoms scores in our study are quite high. The regression model shows that gastrointestinal symptoms are most prevalent in the 20-30-year-old age group [odds ratio (OR) = 13.90] and the cigarette-smoking group (OR = 8.52). The most important factors affecting the prevalence of cardiovascular symptoms are marital status (OR = 2.41) and smoking (OR = 2.31).

CONCLUSION

The findings might help occupational health nurses and other occupational health-care personnel in assessing high-risk nurses who could benefit from interventions aimed at minimizing gastrointestinal and cardiovascular disorders.

Occupational factors and risk of preterm birth in nurses

OBJECTIVE

We evaluated first-trimester exposures and the risk of preterm birth in the most recent pregnancy of participants of the Nurses' Health Study II.

STUDY DESIGN

Log binomial regression was used to estimate the relative risk (RR) for preterm birth in relation to occupational risk factors, such as work schedule, physical factors, and exposures to chemicals and x-rays, adjusted for age and parity.

RESULTS

Part-time work (<or= 20 hours a week) was associated with a lower risk of preterm birth [RR, 0.7; 95% confidence interval [CI], 0.6-0.9]. Working nights was associated only with early preterm birth (< 32 weeks of gestation) (RR, 3.0; 95% CI, 1.4-6.2). Although based on only 11 exposed preterm cases, self-reported exposure to sterilizing agents was associated with an increased risk (RR, 1.9; 95% CI, 1.1-3.4).

CONCLUSION

These data suggest that night work may be related to early but not late preterm birth, whereas physically demanding work did not strongly predict risk.

Standard safety practices for sorting of unfixed cells

Cell sorting of viable biological specimens has become widespread in laboratories involved in basic and clinical research. As these samples can contain infectious agents, precautions to protect instrument operators and the environment from hazards arising from the use of sorters are paramount. This unit presents a revised and updated version of the biosafety guidelines for sorting of unfixed cells established in 1977 by the International Society of Analytical Cytology (ISAC), whose recommendations have become recognized worldwide as the standard practices and safety precautions for laboratories performing viable cell-sorting experiments. The unit contains background information on the biohazard potential of sorting and the hazard classification of infectious agents as well as recommendations on (1) sample handling, (2) operator training and personal protection, (3) laboratory design, (4) cell sorter setup, maintenance, and decontamination, and (5) testing the instrument for the efficiency of aerosol containment.

International Society for Analytical Cytology biosafety standard for sorting of unfixed cells

BACKGROUND

Cell sorting of viable biological specimens has become very prevalent in laboratories involved in basic and clinical research. As these samples can contain infectious agents, precautions to protect instrument operators and the environment from hazards arising from the use of sorters are paramount. To this end the International Society of Analytical Cytology (ISAC) took a lead in establishing biosafety guidelines for sorting of unfixed cells (Schmid et al., Cytometry 1997;28:99-117). During the time period these recommendations have been available, they have become recognized worldwide as the standard practices and safety precautions for laboratories performing viable cell sorting experiments. However, the field of cytometry has progressed since 1997, and the document requires an update.

METHODS

Initially, suggestions about the document format and content were discussed among members of the ISAC Biosafety Committee and were incorporated into a draft version that was sent to all committee members for review. Comments were collected, carefully considered, and incorporated as appropriate into a draft document that was posted on the ISAC web site to invite comments from the flow cytometry community at large. The revised document was then submitted to ISAC Council for review. Simultaneously, further comments were sought from newly-appointed ISAC Biosafety committee members.

RESULTS

This safety standard for performing viable cell sorting experiments was recently generated. The document contains background information on the biohazard potential of sorting and the hazard classification of infectious agents as well as recommendations on (1) sample handling, (2) operator training and personal protection, (3) laboratory design, (4) cell sorter set-up, maintenance, and decontamination, and (5) testing the instrument for the efficiency of aerosol containment.

CONCLUSIONS

This standard constitutes an updated and expanded revision of the 1997 biosafety guideline document. It is intended to provide laboratories involved in cell sorting with safety practices that take into account the enhanced hazard potential of high-speed sorting. Most importantly, it states that droplet-based sorting of infectious or hazardous biological material requires a higher level of containment than the one recommended for the risk group classification of the pathogen. The document also provides information on safety features of novel instrumentation, new options for personal protective equipment, and recently developed methods for testing the efficiency of aerosol containment.

Occupational exposures and haematological malignancies: overview on human recent data

OBJECTIVE

Occupational causes of haematological malignancies are relatively uncommon, under-studied and under-identified. They are also often unrecognized by clinicians. This review summarizes the principal epidemiologic studies on this topic.

METHODS

We analyzed the recent relevant human data found in the Medline, the Pascal and the BDSP databases.

RESULTS

Benzene and ionizing radiation are the only agents conclusively demonstrated to be carcinogenic to the haematopoietic system. In particular, both exposures are strongly associated with acute myeloid leukaemia. Low doses of both may also be related to myeloid malignancies. Infectious agents and pesticides are also thought to induce lymphoproliferative cancers. Some studies show an association between haematological malignancies and low-frequency electromagnetic fields and organic solvents. All of these suspected occupational causes must be confirmed by further studies.

CONCLUSIONS

Better knowledge and understanding of occupational causes of haematological malignancies are necessary to improve their prevention and compensation.

A fluorescence bioassay to detect residual formaldehyde from clinical materials sterilized with low-temperature steam and formaldehyde

A microtiter plate toxicity test based on fluorescence was developed to determine the residual concentration of formaldehyde on medical items after LTSF sterilization. The residual formaldehyde on eight common materials, some of which are used in different clinical instruments and devices were analysed after sterilization with LTSF. Formaldehyde residues were detected on cotton, filter paper, natural rubber, PVC, and silicone-coated latex, but not on polyurethane, silicone or glass. Formaldehyde never exceeded the recommended maximum concentration on clinical devices of about 5 microg/cm2. The results were compared with those obtained by means of a chemical method, the correlation being good (R2=0.9396). The biological method proposed here is fast and can be automated, which means that it could be used as a screening method when there are doubts as to the accumulation of residues on clinical materials or instruments that are going to be sterilized with LTSF.

Assessing the health implications for healthcare workers of regulatory changes eliminating locally developed occupational exposure limits in favor of TLVs: an evidence-based bipartite approach

In response to the intention of the Workers' Compensation Board of British Columbia (WCB of BC) to eliminate made-in-BC occupational exposure limits (OELs) and adopt threshold limit values (TLVs), this study assessed the potential health impacts on healthcare workers (HCWs) of the proposed change, by (1) reviewing the processes used to establish the OELs and TLVs, (2) selecting of substances of health concern for HCWs, (3) identifying chemicals with discordances between existing OELs and the 2002 TLVs, and 4) reviewing the discordances and assessing the potential health implications. Differences in philosophies, policies and processes that influenced the setting of OELs and TLVs were substantial. The TLV process involves U.S. and international priorities; in BC, a tripartite committee determined OELs taking into consideration how OELs should be interpreted in the local context. 47 chemicals of concern to BC HCWs were discordant, with significant discordances totalling 57; 15 compounds had BC 8-hour OELs lower than their respective TLVs and three TLVs were lower than the 8-hour BC OELs. Review of six chemicals with discordances suggested a potential for increased risks of adverse health effects. Eliminating the local capacity and authority to set OELs is unlikely to cause major health problems in the short run, but as chemicals in use locally may not have up-to-date TLVs, eliminating the capacity for local considerations should be undertaken with great caution. While the WCB of BC did implement the change, the present report resulted in procedural changes that will provide better protection for the workforce.

Biosafety concerns for shared flow cytometry core facilities

Many researchers who need flow cytometry for their projects have neither sufficient funds nor the work volume to justify the purchase of an analytic cytometer or cell sorter. In shared flow cytometry facilities, costs for instrument purchases, cytometer maintenance, and personnel are pooled to provide economic services for a multitude of users when they are required. Owing to the diverse nature of the samples that are submitted to core facilities, the biohazard potential of the samples can vary dramatically. For the safety of facility personnel and users, it is critical that information about hazards contained in the samples be transmitted to instrument operators before flow cytometry experiments are started. During 1999 the former Biosafety Committee of the International Society for Analytical Cytology formulated a framework biosafety questionnaire for shared facilities designed to request information about the hazard potential of experimental samples from investigators who wish to use the facility. In this report we review safety issues that are pertinent to flow cytometry core facilities by discussing the individual components of this biosafety questionnaire.

Cancer incidence among laboratory workers in biomedical research and routine laboratories in Israel: Part II-nested case-control study

BACKGROUND

A case-control study nested within a cohort study of biomedical laboratory workers was conducted to examine whether the excess cancer morbidity that we found can be explained by exposure to a particular group of substances, taking into consideration potential confounders.

METHODS

The study population included 163 cases and two matched control groups: laboratory workers (311) and general population (448) workers.

RESULTS

Multiple conditional regression analysis showed that working in research laboratories involved an increased risk of cancer generally among women [risk ratio 2.2 (1.2-4.3)], and of breast cancer particularly [risk ratio 2.3 (1.1-4.7). Seventy-six percent (76%) of breast, 87% of thyroid, 60% of ovary and prostate, 94% of melanoma, and 50% of leukemia cases were ever exposed to at least one known human carcinogen.

CONCLUSION

Our results exclude the possibility that the excess cancer morbidity was related to personal risk factors but they may be explained by exposure factors. Am. J. Ind. Med. 44:611-626, 2003.

Cancer incidence among laboratory workers in biomedical research and routine laboratories in Israel: Part I-the cohort study

BACKGROUND

Laboratory work is associated with exposure to a mixture of carcinogens.

METHODS

The cohort is comprised of 4,300 laboratory workers. Cancer incidence was followed from 1960 to 1997.

RESULTS

A total of 230 cases were included in the cohort. The overall cancer standardized incidence ratio (SIR) was 1.04 (0.91-1.18). When a 20-year latency was introduced, SIR was increased significantly: 1.35 (1.13-1.61). Among routine workers and researchers, SIR was elevated significantly for the total population and for women, when a 20-year latency was introduced. SIR was also elevated significantly in research, routine, bacteriology and virology, and isotope laboratories. With respect to specific sites, significantly increased SIR was observed in breast, ovary, and thyroid cancer among women; and prostate cancer, leukemia, and melanoma among men.

CONCLUSIONS

We suggest that work in research and biomedical laboratories might involve an increased risk of certain types of cancer. Am. J. Ind. Med. 44:600-610, 2003.