George L. Delclos

Associations between temporary employment and occupational injury: what are the mechanisms?

Objective: To determine whether observed higher risks of occupational injury among temporary workers are due to exposure to hazardous working conditions and/or to lack of job experience level. Methods: Data systematically recorded for 2000 and 2001 by the Spanish Ministry of Labour and Social Affairs on fatal and non-fatal traumatic occupational injuries were examined by type of employment and type of accident, while adjusting for gender, age, occupation, and length of employment in the company. In the study period there were 1500 fatal and 1 806 532 non-fatal traumatic occupational injuries that occurred at the workplace. Incidence rates and rate ratios (RR) were estimated using Poisson regression models. Results: Temporary workers showed a rate ratio of 2.94 for non-fatal occupational injuries (95% CI 2.40 to 3.61) and 2.54 for fatal occupational injuries (95% CI 1.88 to 3.42). When these associations were adjusted by gender, age, occupation, and especially length of employment, they loose statistic significance: 1.05 (95% CI 0.97 to 1.12) for non-fatal and 1.07 (95% CI 0.91 to 1.26) for fatal. Conclusions: Lower job experience and knowledge of workplace hazards, measured by length of employment, is a possible mechanism to explain the consistent association between temporary workers and occupational injury. The role of working conditions associated with temporary jobs should be assessed more specifically.

Compliance with universal precautions among physicians

This study characterized and assessed self-reported levels of compliance with universal precautions (UP) among hospital-based physicians, and determined significant factors associated with both compliance and noncompliance. The physicians (n = 322) were a subgroup of a larger study population of hospital-based health care workers recruited from three geographically distinct locations (n = 1746), and were surveyed using a detailed confidential questionnaire that assessed personal, work-related, and organizational factors. Compliance with UP was measured through 11 items that examined how often physicians followed specific recommended work practices. Compliance was found to vary among the 11 items: they were high for certain activities (eg, glove use, 94%; disposal of sharps, 92%) and low for others (eg, wearing protective clothing, 55%; not recapping needles, 56%). Compliance with all items was low (31% to 38%). Stepwise logistic regression revealed that noncompliant physicians were likely to be age 37 or older, to report high work stress, and to perceive a conflict of interest between providing patient care and protecting themselves. Compliant physicians were more likely to be knowledgeable and to have been trained in universal precautions, to perceive protective measures as being effective, and to perceive an organizational commitment to safety.

Disabling musculoskeletal pain in working populations: is it the job, the person, or the culture?

&NA; Large international variation in the prevalence of disabling forearm and low back pain was only partially explained by established personal and socioeconomic risk factors. &NA; To compare the prevalence of disabling low back pain (DLBP) and disabling wrist/hand pain (DWHP) among groups of workers carrying out similar physical activities in different cultural environments, and to explore explanations for observed differences, we conducted a cross‐sectional survey in 18 countries. Standardised questionnaires were used to ascertain pain that interfered with everyday activities and exposure to possible risk factors in 12,426 participants from 47 occupational groups (mostly nurses and office workers). Associations with risk factors were assessed by Poisson regression. The 1‐month prevalence of DLBP in nurses varied from 9.6% to 42.6%, and that of DWHP in office workers from 2.2% to 31.6%. Rates of disabling pain at the 2 anatomical sites covaried (r = 0.76), but DLBP tended to be relatively more common in nurses and DWHP in office workers. Established risk factors such as occupational physical activities, psychosocial aspects of work, and tendency to somatise were confirmed, and associations were found also with adverse health beliefs and group awareness of people outside work with musculoskeletal pain. However, after allowance for these risk factors, an up‐to 8‐fold difference in prevalence remained. Systems of compensation for work‐related illness and financial support for health‐related incapacity for work appeared to have little influence on the occurrence of symptoms. Our findings indicate large international variation in the prevalence of disabling forearm and back pain among occupational groups carrying out similar tasks, which is only partially explained by the personal and socioeconomic risk factors that were analysed.

Association between cleaning-related chemicals and work-related asthma and asthma symptoms among healthcare professionals

Objectives Work-related asthma (WRA) is an important public health problem affecting one quarter of adults with asthma. Although cleaning substances are routinely used in hospitals, few studies have addressed their potential adverse respiratory health effects on healthcare professionals (HCPs). This study attempts to identify relationship between work-related exposure to cleaning-related chemicals and development of WRA among HCPs. Methods Of 5600 HCPs surveyed, 3650 responded to a validated questionnaire about their occupation, asthma diagnosis, variability of asthma symptoms at and away from work, and exposure to individual cleaning substances. Workplace asthma was defined as a categorical variable with four mutually exclusive categories: work-related asthma symptoms (WRAS), work-exacerbated asthma (WEA), occupational asthma (OA) and none. Multivariable logistic regression analysis was used to evaluate the association between self-reported use of cleaning substances and asthma outcomes among HCPs. Results Prevalences of WRAS, WEA and OA were 3.3%, 1.1% and 0.8%, respectively. The prevalence estimates were generally higher among female than male HCPs. The odds of WRAS and WEA increased in a dose-dependent manner for exposure in the longest job to cleaning agents and disinfectants/sterilants, respectively. For exposure in any job, the odds of WRAS were significantly elevated for both factor 1 (bleach, cleaners/abrasives, toilet cleaners, detergents and ammonia) and factor 2 (glutaraldehyde/ortho-phtaldehyde, chloramines and ethylene oxide). Significantly elevated odds of WEA were observed for exposure to bleach, factor 2 and formalin/formaldehyde. Exposure to chloramines was significantly associated with an almost fivefold elevated odds of OA. Conclusions HCPs are at risk of developing WRA from exposure to cleaning substances.

Prevalence and risk factors of work related asthma by industry among United States workers: data from the third national health and nutrition examination survey (1988–94)

Objectives: To estimate the prevalence of work related asthma and work related wheezing in United States workers. To identify high risk industries that could be targeted for future intervention. To determine the population attributable risk of work related asthma and work related wheezing. Methods: The third national health and nutrition examination survey, 1988–1994 (NHANES III) was analyzed to determine the prevalence of work related asthma and wheezing and to identify initially defined industries at risk among United States workers aged 20 and older. Separate logistic models were developed with work related asthma and work related wheezing as outcomes. Work related asthma was defined as affirmative response to questions on self reported physician diagnosed asthma and work related symptoms of rhinitis, conjunctivitis, and asthma. Work related wheezing was defined as affirmative response to questions on self reported wheezing or whistling in the chest in the previous 12 months and work related symptoms of rhinitis, conjunctivitis, and asthma. All analyses were adjusted for age, sex, smoking, and atopy. Results: The prevalence of work related asthma was 3.70% (95% confidence interval (95% CI) 2.88 to 4.52) and the prevalence of work related wheezing was 11.46% (95% CI 9.87 to 13.05). The main industries identified at risk of work related asthma and wheeze included the entertainment industry; agriculture, forestry, and fishing; construction; electrical machinery; repair services; and lodging places. The population attributable risk for work related asthma was 36.5% and work related wheezing was 28.5%. Conclusions: The findings provide impetus for further research and actions by public health professionals which prioritise occupational asthma on the public health agenda. Future intervention strategies need to be developed for effective control and prevention of asthma in the workplace.

Prevalence of Asthma among Adult Females and Males in the United States: Results from the National Health and Nutrition Examination Survey (NHANES), 2001–2004

BACKGROUND The prevalence of asthma has increased over the last three decades with females exhibiting a higher prevalence of asthma than males. The objective of this study was to obtain gender-specific estimates of the prevalence of current and ever asthma and describe the relationships between risk factors and asthma by gender in US men and women ages 20 to 85. METHODS Data for this study came from two cycles (2001-2002 and 2003-2004) of National Health and Nutrition Examination Survey (NHANES) and included 9,243 eligible adults: 4,589 females and 4,654 males. Multiple logistic regression was used to investigate gender-specific associations between race/ethnicity, body mass index (BMI), sociodemographic characteristics, and smoking habits for current asthma and ever asthma. RESULTS The prevalence of current asthma was 8.8% for women and 5.8% for men, while the prevalence of ever having been diagnosed with asthma was higher (13.7% and 10.4% for women and men, respectively). Current asthma was less prevalent in Mexican American women (1.9%) and men (0.9%) born in Mexico as compared to Mexican Americans born in the U.S. (8.7% and 5.2% for women and men, respectively) or for any other ethnic group. Approximately 20% of extremely obese women and men had ever been diagnosed with asthma; among this group, 15% reported they had current asthma. Results from multiple logistic regression models indicate that extreme obesity and living in poverty were strongly associated with current and ever asthma for both women and men, as was former smoking and ever asthma for men. CONCLUSION As compared to previous NHANES reports, our results indicate that the prevalence of asthma among U.S. adults continues to increase. Further, our findings of marked differences among subgroups of the population suggest asthma-related disparities for impoverished persons and greater prevalence of asthma among obese and extremely obese US adults.

Dietary Intakes of Zinc and Heme Iron from Red Meat, but Not from Other Sources, Are Associated with Greater Risk of Metabolic Syndrome and Cardiovascular Disease

Metabolic syndrome (MetS), Type 2 diabetes (T2D), and cardiovascular disease (CVD) share an inflammatory etiology and are known to be influenced by diet. We investigated associations of hypothesized prooxidative (Fe) and antioxidative (Zn, Mg, β-carotene, vitamin C, vitamin E) micronutrients with incident MetS, T2D, and CVD in the Multi-Ethnic Study of Atherosclerosis. Participants, 45-84 y at baseline (2000-2002), were followed through 2010. Diet was assessed by FFQ. After adjusting for demographics and behavioral confounders, including BMI, dietary vitamin E intake was inversely associated with incident MetS and CVD [HR for extreme quintiles: MetS = 0.78 (95% CI = 0.62, 0.97), P-trend = 0.01; CVD: HR = 0.69 (95% CI = 0.46, 1.03), P-trend = 0.04]. Intakes of heme iron and Zn from red meat, but not from other sources, were positively associated with risk of MetS [heme iron from red meat: HR = 1.25 (95% CI = 0.99,1.56), P-trend = 0.03; Zn from red meat: HR = 1.29 (95% CI = 1.03,1.61), P-trend = 0.04] and CVD [heme iron from red meat: HR = 1.65 (95% CI = 1.10,2.47), P-trend = 0.01; Zn from red meat: HR = 1.51 (95% CI = 1.02, 2.24), P-trend = 0.01]. Dietary intakes of nonheme iron, Mg, vitamin C, and β-carotene were not associated with risk of MetS, T2D, or CVD. Data provided little support for the associations between specific micronutrients and MetS, T2D, or CVD. However, nutrients consumed in red meat, or red meat as a whole, may increase risk of MetS and CVD.

Genetic variations in PI3K-AKT-mTOR pathway and bladder cancer risk

Genetic variations in phosphoinositide-3 kinase (PI3K)-AKT-mammalian target of rapamycin (mTOR) pathway may affect critical cellular functions and increase an individuals cancer risk. We systematically evaluate 231 single-nucleotide polymorphisms (SNPs) in 19 genes in the PI3K-AKT-mTOR signaling pathway as predictors of bladder cancer risk. In individual SNP analysis, four SNPs in regulatory associated protein of mTOR (RAPTOR) remained significant after correcting for multiple testing: rs11653499 [odds ratio (OR): 1.79, 95% confidence interval (CI): 1.24-2.60, P = 0.002], rs7211818 (OR: 2.13, 95% CI: 1.35-3.36, P = 0.001), rs7212142 (OR: 1.57, 95% CI: 1.19-2.07, P = 0.002) and rs9674559 (OR: 2.05, 95% CI: 1.31-3.21, P = 0.002), among which rs7211818 and rs9674559 are within the same haplotype block. In haplotype analysis, compared with the most common haplotypes, haplotype containing the rs7212142 wild-type allele showed a protective effect of bladder cancer (OR: 0.83, 95% CI: 0.70-0.97). In contrast, the haplotype containing the rs7211818 variant allele showed a 1.32-fold elevated bladder cancer risk (95% CI: 1.09-1.60). In combined analysis of three independent significant RAPTOR SNPs (rs11653499, rs7211818 and rs7212142), a significant trend was observed for increased risk with an increase in the number of unfavorable genotypes (P for trend <0.001). Compared with the subjects without any of the unfavorable genotypes, those carrying all three unfavorable genotypes showed a 2.22-fold (95% CI: 1.33-3.71) increased bladder cancer risk. This is the first study to evaluate the role of germ line genetic variations in PI3K-AKT-mTOR pathway as cancer susceptibility factors that will help us identify high-risk individuals for bladder cancer.

Link between allergic asthma and airway mucosal infection suggested by proteinase-secreting household fungi

Active fungal proteinases are powerful allergens that induce experimental allergic lung disease strongly resembling atopic asthma, but the precise relationship between proteinases and asthma remains unknown. Here, we analyzed dust collected from the homes of asthmatic children for the presence and sources of active proteinases to further explore the relationship between active proteinases, atopy, and asthma. Active proteinases were present in all houses and many were derived from fungi, especially Aspergillus niger. Proteinase-active dust extracts were alone insufficient to initiate asthma-like disease in mice, but conidia of A. niger readily established a contained airway mucosal infection, allergic lung disease, and atopy to an innocuous bystander antigen. Proteinase produced by A. niger enhanced fungal clearance from lung and was required for robust allergic disease. Interleukin 13 (IL-13) and IL-5 were required for optimal clearance of lung fungal infection and eosinophils showed potent anti-fungal activity in vitro. Thus, asthma and atopy may both represent a protective response against contained airway infection due to ubiquitous proteinase-producing fungi.

Descriptive Epidemiology of Somatising Tendency: Findings from the CUPID Study

Somatising tendency, defined as a predisposition to worry about common somatic symptoms, is importantly associated with various aspects of health and health-related behaviour, including musculoskeletal pain and associated disability. To explore its epidemiological characteristics, and how it can be specified most efficiently, we analysed data from an international longitudinal study. A baseline questionnaire, which included questions from the Brief Symptom Inventory about seven common symptoms, was completed by 12,072 participants aged 20–59 from 46 occupational groups in 18 countries (response rate 70%). The seven symptoms were all mutually associated (odds ratios for pairwise associations 3.4 to 9.3), and each contributed to a measure of somatising tendency that exhibited an exposure-response relationship both with multi-site pain (prevalence rate ratios up to six), and also with sickness absence for non-musculoskeletal reasons. In most participants, the level of somatising tendency was little changed when reassessed after a mean interval of 14 months (75% having a change of 0 or 1 in their symptom count), although the specific symptoms reported at follow-up often differed from those at baseline. Somatising tendency was more common in women than men, especially at older ages, and varied markedly across the 46 occupational groups studied, with higher rates in South and Central America. It was weakly associated with smoking, but not with level of education. Our study supports the use of questions from the Brief Symptom Inventory as a method for measuring somatising tendency, and suggests that in adults of working age, it is a fairly stable trait.