Further round-robin tests to improve the comparability between laboratories of the measurement of carbon in diesel soot and in environmental samples

Objectives: An informal European coordination group organized two round-robin tests on filters collected from environmental, workplace and diluted diesel emissions. Previous inter-laboratory comparisons have shown that experimental samples give reasonably good results in terms of the dispersion around the mean, from all the participating laboratories. However, there were significant differences between the laboratories owing to a narrow distribution of the results within a single laboratory. In order to gain a better understanding of the differences obtained between the laboratories, it was decided to carry out more round-robin tests and to investigate further the possible factors which may influence the results. Methods: The first round-robin (RRT3) was performed on six different samples (eight replicates) analyzed by ten laboratories. The range of loading was 40 to 138 μg cm⁻² of total carbon (TC). Laboratories used their own thermal procedure parameters. The second round-robin test (RRT4) was performed on three different diluted diesel emissions (two replicates) samples analyzed by 13 laboratories. The range of loading was 21 to 37 μg cm⁻² TC. Laboratories analyzed samples using imposed temperatures (500, 650 and 800 °C) and imposed duration (12 min). Results: Inter-laboratory coefficients of variation for diluted diesel emission samples were 10% for RRT3 and ranged from 6 to 19% for RRT4. The influence of the desorption temperature was clearly demonstrated and the results tended to show that a desorption temperature of 650 °C could be an acceptable compromise. The influence of the organic carbon/elemental carbon (OC/EC) ratio was shown to be insignificant with pure diesel soot samples. Conclusions: It was expected that a significant improvement would be seen in the inter-laboratory dispersion by the use of a common standardized thermal desorption program, but the objectives of these RRTs were only partly reached. This paper provides new information that will be useful in the elaboration of a standardized procedure for the European Normalisation Centre (CEN TC 137 WG2 – General requirements for measuring procedures). Received: 14 April 2000 / Accepted: 26 July 2000     

Evaluation of biodiesel’s impact on real-world occupational and environmental particulate matter exposures at a municipal facility in Keene, NH

Many organizations are interested in biodiesel as a renewable, domestic energy source for use in transportation and heavy-duty equipment. Although numerous biodiesel emission studies exist, biodiesel exposure studies are nearly absent from the literature. This study compared the impact of petroleum diesel fuel and a B20 blend (20% soy-based biodiesel/80% petroleum diesel) on occupational and environmental exposures at a rural municipal facility in Keene, NH. For each fuel type, we measured concentrations of fine particulate matter (PM_2.5), elemental carbon (EC), and organic carbon (OC) at multiple locations (in-cabin, work area, and near-field) at a materials recovery facility utilizing non-road equipment. B20 fuel use resulted in significant reductions in PM_2.5 mass (56–76%), reductions in EC (5–29%), and increases in OC (294–467%). Concentrations of PM_2.5 measured during petroleum diesel use were up to four times higher than PM_2.5 concentrations during B20 use. Further analysis of the EC and OC fractions of total carbon also indicated substantial differences between fuels. Our results demonstrate that biodiesel blends significantly reduced PM_2.5 exposure compared to petroleum diesel fuel in a workplace utilizing non-road construction-type equipment. While this suggests that biodiesel may reduce health risks associated with exposure to fine particulate matter mass, more exposure research is needed to better understand biodiesel-related changes in particulate matter composition and other exposure metrics.     

Biological monitoring of workers exposed to 4,4′-methylene-bis-(2-orthochloroaniline) (MOCA)

Objective: The objective of the study was to validate a new and simple method to determine MOCA in the urine of exposed workers. Methods: The separation, identification and quantification of urinary MOCA were performed in spiked urines by a sensitive and practical high-performance liquid chromatography (HPLC) method and applied to urine samples of 11 workers occupationally exposed to MOCA; the postshift urinary levels of MOCA in their urine samples with and without hydrolysis, “total” and “free” MOCA respectively, were determined. In addition, we investigated the use of citric or sulfamic acid as preservatives of urine samples. Results: The “total” and “free” MOCA were extracted with isooctane from hydrolysed and nonhydrolysed 20-ml urine samples respectively. After evaporation, the residue was dissolved in 4 ml of 2 · 10⁻² M aqueous hydrochloric acid and analysed by an isocratic HPLC system using both ultraviolet (UV) detection at 244 nm and electrochemical detection working in oxidation mode (0.9 V) with an Ag/AgCl reference electrode. Mobile phase (50% acetonitrile in water containing 0.4% acetate buffer solution pH = 4.6) was used to complete the 20-min analysis. “Free” and “total” MOCA were chromatographed on a reversed-phase C8 column (5 μm; 250 mm × 4 mm). The standard curve of MOCA was linear over the range 5–500 μg/l in human urine. The detection limit was 1 μg/l for a 20-μl injection volume; the repeatability ranged from 5.6 to 1.3% (n = 6) for spiked urines at 5 and 500 μg/l, with a percentage recovery of 94 ± 3%. The reproducibility of the method was 7.3% (n = 4) for spiked urine at 10 μg/l. The use of sulfamic acid as a preservative of urine samples is important to improve the precision and accuracy of the analysis. Conclusion: The results indicate that these analytical procedures using conventional apparatus may be used routinely and reliably with large numbers of urine samples for biological monitoring of the exposure to MOCA. The occupational exposure to MOCA in some factories in France is studied in the second part of this work. Received: 10 November 1998 / Accepted: 25 March 1999     

Determination of N-nitrosodiethanolamine in urine by gas chromatography thermal energy analysis: application in workers exposed to aqueous metalworking fluids

 Objective: The aim of this study was to describe a detailed and validated methodology designed for the analysis of carcinogenic N-nitrosodiethanolamine (NDELA) down to sub-μg/l levels in urine and its application to a number of workers exposed to NDELA-contaminated aqueous metalworking fluids (MWF). Methods: Following a work-up procedure based on solid-phase extraction of NDELA, the urinary extracts were analysed without derivatization by gas chromatography on a polar wide-bore column with chemiluminescent detection using a thermal energy analyser (TEA). N-Nitroso-(2-hydroxypropyl)amine was used as an internal standard. The method was applied to 12 workers using “nitrite-free” or “nitrite-formulated” MWF and to 15 unexposed subjects. The NDELA content of the MWF was also determined using a similar, but simpler method able to easily quantify NDELA down to at least 0.1 mg/l. Results: Contamination by NDELA traces of some chemicals used for the sample preparation, particularly ethyl formate, must be carefully checked since it can give rise to false-positive results of up to 1 or 2 μg/l. The response was linear in the range of 0–500 μg/l. Between 0.5 and 10 μg/l, the recovery rate was close to 95%, while repeatability ranged from 12.5 to 6.4% (n = 5). The detection limit was 0.3 μg/l (Signal/noise = 3). No detectable NDELA could be observed in the control workers. There was no significant increase in NDELA levels at the end of shift spot samples from an exposed worker over 1 week. Higher NDELA concentrations were found in two workers (4.3 and 10.7 μg/l) exposed to “nitrite-formulated” fluids (contaminated with 65 and 18 mg NDELA per l, respectively) than in nine workers (range, 0.4–1.3 μg/l exposed to “nitrite-free” fluids with lower levels of NDELA (range, 0.5–6.6 mg/l). Conclusion: The detailed methodology described in this work and applied to a limited industrial situation was found to be suitable for monitoring NDELA in the urine of workers exposed to aqueous MWF. A much larger screening has been undertaken with the aim of obtaining better information on the real exposure of workers sometimes exposed to “nitrite-formulated” fluids that are still used. Received: 8 December 1998 / Accepted: 3 April 1999     

Criteria for estimating acceptable exposure times in hot working environments: a review

Objectives: To revise the criteria used in the present “Required Sweat Rate” standard ISO 7933 (1989) for the prediction of the maximum duration of work in hot environments. Methods: Review of the literature and in particular, of the bases for the present criteria. Results: A new method is proposed, to take into account the increase in core temperature associated with activity in neutral environments. The prediction of maximum wetness and maximum sweat rates are revised, as well as the limits for maximum water loss and core temperature. Conclusion: An improved set of maximum values and limits is described, to be used in the revised version of the ISO 7933 standard. Due to the major modifications to the “Required Sweat Rate” index and in order to avoid any confusion, it is suggested that the revised model be renamed the “Predicted Heat Strain” (PHS) model. Received: 14 October 1999 / Accepted: 2 November 1999     

Prevalence and incidence of hand dermatitis in hairdressing apprentices: results of the POSH study

Objective: Occupational skin changes in hairdressers are very common. Morbidity, however, has not yet been quantified precisely. Methods: A cohort of 2,352 hairdressing apprentices (of the 2,570 invited to participate, i.e., 91.5% response) was prospectively followed for the duration of their vocational training (3 years) by three examinations. Three waves (years) were recruited in 1992, 1993, and 1994 from 15 vocational training schools in northwestern Germany. Results: The point prevalence of (mostly slight) irritant skin changes of the hands increased from 35.4% in the initial examination to 47.5% in the intermediate examination and to 55.1% in the final examination. Given a more conservative definition of a case of “hand dermatitis,” these estimates were 12.9%, 23.5%, and 23.9%, respectively. Altogether, 34.3 and 15.2 cases of “skin changes (any degree)” and “hand dermatitis,” respectively, in 100 person-years were observed during the study period. The incidence rate, i.e., the number of newly diseased study participants in relation to the person-time at risk contributed, decreased in the course of the study. The proportion of dropouts until final follow-up was 51.8%. Conclusion: The present results appear to lie in a range with those found in other, much smaller cohort studies. However, comparison of the results is hampered either by the lack of a clear definition or by a different definition of “person-time at risk” or “a case of hand dermatitis.” As compared with an external control group of office apprentices, the incidence was several times higher in hairdressing apprentices, which points to the high risk for skin damage in this occupation. Received: 15 December 1997 / Accepted: 8 May 1998     

Environmental exposure of small children to polycyclic aromatic hydrocarbons

Objectives: The aim of the study was to assess the intake (by various routes of exposure) of polycyclic aromatic hydrocarbons (PAH) by children living in a Czech city, and its effect on excretion of 1-hydroxypyrene (1-OHP) in summer and winter periods. Methods: Four groups of children (3–6 years old) were chosen: (1) two groups from a kindergarten situated in the city center with a higher traffic density (“polluted” area); (2) two groups from a kindergarten situated in a green zone of the same city (“non-polluted” area). Food consumption was recorded in all children and PAH intake from foodstuffs was estimated. Ambient air samples were collected from the playground and inside the kindergartens. Soil samples were collected too. Morning and evening urine samples were collected during sampling days. Results: In both seasons, the mean outdoor total PAH concentration (sum of 12 individual PAH) in the “polluted” area was approximately three-times higher than that in the “non-polluted” area. Indoor concentration in the “polluted” area was more than six-times higher than that in the “non-polluted” area in summer, and almost three-times higher in winter. The same trend was observed for pyrene and for the sum of carcinogenic PAH. The contribution to the total pyrene absorbed dose from food consumption was much more important than that from inhalation and from ingestion of soil dust. Significantly higher urinary concentrations of 1-OHP (evening samples) were found in children from the “polluted” kindergarten in both seasons. The number of significant relationships between 1-OHP and pyrene absorbed dose was weak. Conclusions: Food seems to be the main source of total pyrene and total PAH intake in small children, even under relatively higher air PAH exposure in the city. Estimated pyrene ingestion from soil had a negligible contribution to the total pyrene absorbed dose. Urinary 1-OHP seems to be an uncertain (non-sensitive) marker of the environmental inhalation exposure to pyrene (PAH) if the pollution of air by pyrene (PAH) is not excessive and the pyrene (PAH) dose by this route is much less than by ingestion. Usefulness of the urinary 1-OHP as an indicator of overall environmental exposure to PAH needs further investigation. Received: 18 September 2000 / Accepted: 20 February 2001     

Towards Global Age-Friendly Cities: Determining Urban Features that Promote Active Aging

At the same time as cities are growing, their share of older residents is increasing. To engage and assist cities to become more “age-friendly,” the World Health Organization (WHO) prepared the Global Age-Friendly Cities Guide and a companion “Checklist of Essential Features of Age-Friendly Cities”. In collaboration with partners in 35 cities from developed and developing countries, WHO determined the features of age-friendly cities in eight domains of urban life: outdoor spaces and buildings; transportation; housing; social participation; respect and social inclusion; civic participation and employment; communication and information; and community support and health services. In 33 cities, partners conducted 158 focus groups with persons aged 60 years and older from lower- and middle-income areas of a locally defined geographic area (n = 1,485). Additional focus groups were held in most sites with caregivers of older persons (n = 250 caregivers) and with service providers from the public, voluntary, and commercial sectors (n = 515). No systematic differences in focus group themes were noted between cities in developed and developing countries, although the positive, age-friendly features were more numerous in cities in developed countries. Physical accessibility, service proximity, security, affordability, and inclusiveness were important characteristics everywhere. Based on the recurring issues, a set of core features of an age-friendly city was identified. The Global Age-Friendly Cities Guide and companion “Checklist of Essential Features of Age-Friendly Cities” released by WHO serve as reference for other communities to assess their age readiness and plan change.     

What Makes a Respondent-Driven Sampling “Seed” Productive? Example of Finding At-Risk Massachusetts Men Who Have Sex with Men

Several recent studies have sought to elaborate upon the applicability and validity of respondent-driven sampling (RDS) to find hard-to-reach samples in general and men who have sex with men (MSM) in particular. Few published studies have elucidated the characteristics associated with initial RDS participants (“seeds”) who successfully recruited others into a study. A total of 74 original seeds were analyzed from four Massachusetts studies conducted between 2006 and 2008 that used RDS to reach high-risk MSM. Seeds were considered “generative” if they recruited two or more subsequent participants and “non-generative” if they recruited zero or one participant. Overall, 34% of seeds were generative. In separate multivariable logistic regression models controlling for age, race, health insurance, HIV status, and the study for which the seed was enrolled, unprotected anal sex in the past 12 months [adjusted odds ratio (AOR) = 6.68; 95% confidence interval (95% CI) = 1.27–35.12; p = 0.03], cocaine use during sex at least monthly during the past 12 months (AOR = 8.81; 95% CI = 1.68–46.27; p = 0.01), and meeting sex partners at social gatherings (AOR = 7.42; 95% CI = 1.58–34.76; p = 0.01) and public cruising areas (AOR = 4.92; 95% CI = 1.27–19.01; p = 0.02) were each significantly associated with increased odds of being a generative seed. These findings have methodological and practical implications for the recruitment of MSM via RDS. Finding ways to identify RDS seeds that are consistently generative may facilitate collecting a sample that is closer to reflecting the MSM who live in all of the communities in a given location or study sample.     

Benzene in environmental air and human blood

To study the blood benzene levels resulting from environmental and occupational benzene exposure. Methods: Benzene in venous blood was measured in 243 nonoccupationally exposed subjects (“normal” people) and in 167 workers occupationally exposed to benzene. All exposed workers gave blood samples at the end of the work shift and on the following morning before resuming work. Blood benzene was assayed by gas chromatography (GC)-mass spectrometry. Occupational benzene exposure was monitored by environmental personal samplers and measured by GC analysis. Results: The mean occupational benzene exposure for all 167 workers studied was 186 ng/l (58 ppb; range 5–1535 ng/l, 2–500 ppb). Overall, the mean blood benzene level of all workers was 420 ng/l at the end of the shift and 287 ng/l on the morning thereafter. The blood benzene levels measured the morning after turned out to be significantly lower (t = 3.6; P < 0.0001) than those measured at the end of the shift. The mean blood benzene level of the 243 “normal” subjects was 165 ng/l, which was significantly lower than that measured in the workers on the morning thereafter (t=5.8; P < 0.0000001). The mean blood benzene concentration was significantly higher in smokers than in nonsmokers in both the general population (264 versus 123 ng/l) and in the exposed workers. In the group of nonsmoking workers, whose workplace exposure to benzene was lower than 100 ng/l, blood benzene levels were similar (210–202 ng/l) to those measured in the nonsmoking general population (165 ng/l). End-of-shift blood benzene correlated significantly with environmental exposure (y=0.91x + 251; r=0.581; n=162; P < 0.00001). Finally, there was also a significant correlation between blood benzene measured at the end of the shift and that determined on the morning thereafter (y=0.45x + 109; r=0.572; n=156; P < 0.00001). Conclusion: Nonsmoking workers occupationally exposed to benzene at environmental levels lower than 100 ng/l (mean 35 ng/l) and the nonsmoking general population exposed to ubiquitous benzene pollution have similar blood benzene concentrations. This suggests that it is impossible to distinguish between occupational and environmental exposure when the benzene level in the workplace is less than 100 ng/l. Received: 31 December 1997 / Accepted: 4 August 1998     

Intimate Partner Abuse among Gay and Bisexual Men: Risk Correlates and Health Outcomes

Little is known about the patterns and types of intimate partner abuse in same-sex male couples, and few studies have examined the psychosocial characteristics and health problems of gay and bisexual men who experience such abuse. Using a cross-sectional survey sample of 817 men who have sex with men (MSM) in the Chicago area, this study tested the effect of psychological and demographic factors generally associated with intimate partner abuse and examined their relationship to various health problems. Overall, 32.4% (n = 265) of participants reported any form of relationship abuse in a past or current relationship; 20.6% (n = 168) reported a history of verbal abuse (“threatened physically or sexually, publicly humiliated, or controlled”), 19.2% (n = 157) reported physical violence (“hit, kicked, shoved, burned, cut, or otherwise physically hurt”), and 18.5% (n = 151) reported unwanted sexual activity. Fifty-four percent (n = 144) of men reporting any history of abuse reported more than one form. Age and ethnic group were unrelated to reports of abuse. Depression and substance abuse were among the strongest correlates of intimate partner abuse. Men reporting recent unprotected anal sex were more likely to also report abuse, Wald (1, n = 773) = 9.02, p < .05, Odds Ratio (OR) = 1.61, Confidence Interval (CI) = 1.18–2.21. We discuss psychosocial issues faced by gay and bisexual men who experience intimate partner abuse as they may pertain to interventions among this group.     

Maternal-Infant Bedsharing: Risk Factors for Bedsharing in a Population-Based Survey of New Mothers and Implications for SIDS Risk Reduction

Objectives: Maternal-infant bedsharing is a common but controversial practice. Little has been published about who bedshares in the United States. This information would be useful to inform public policy, to guide clinical practice and to help focus research. The objective was to explore the prevalence and determinants of bedsharing in Oregon. Methods. Oregon Pregnancy Risk Assessment Monitoring System (PRAMS) surveys a population-based random sample of women after a live birth. Women were asked if they shared a bed with their infant “always,” “almost always,” “sometimes” or “never.” Results: 1867 women completed the survey in 1998–99 (73.5% weighted response rate). Of the respondents, 20.5% reported bedsharing always, 14.7% almost always, 41.4% sometimes, and 23.4% never. In multivariable logistic regression, Hispanics (adjusted odds ratio [ORa] 1.69, 95% Confidence Interval [CI] 1.17–2.43), blacks (ORa 3.11, 95% CI 2.03–4.76) and Asians/Pacific Islanders (ORa 2.14, 95% CI 1.51–3.03), women who breastfed more than 4 weeks (ORa 2.65, 95% CI 1.72–4.08), had annual family incomes less than $30,000 (ORa 2.44, 95% CI 1.44–4.15), or were single (ORa 1.55, 95% CI 1.03–2.35) were more likely to bedshare frequently (always or almost always). Among Hispanic and black women, bedsharing did not vary significantly by income level. Bedsharing black, American Indian/Alaska Native and white infants were much more likely to be exposed to smoking mothers than Hispanic or Asian/Pacific Islander infants (p < .0001). Conclusions: Bedsharing is common in Oregon. The women most likely to bedshare are non-white, single, breastfeeding and low-income. Non-economic factors are also important, particularly among blacks and Hispanics. Campaigns to decrease bedsharing by providing cribs may have limited effectiveness if mothers are bedsharing because of cultural norms.     

Performance assessment of a passive sampler in industrial atmospheres

In this work we investigate the performances of a passive sampler (GABIE badge) in industrial atmospheres, in accordance with the general specifications of the EN 838 standard. The field experiment was carried out in a paint-manufacturing factory producing a large number of pollutants at the workplaces. A comparison was performed between the results obtained by passive sampling and the conventional tube/pump method (reference method) on nine solvents usually encountered in the different workshops: n-butanol, isobutanol, toluene, ethylbenzene, m-xylene, methylisobutylketone, methylethylketone (MEK), ethyl acetate, butyl acetate. Results were compared by use of the distribution of the relative difference between badge “passive sampling” and tube “active sampling” results (with the latter considered as the reference method). In general, results revealed good agreement between passive and active sampling (except in the case of MEK) and confirmed the accuracy of sampling rates determined for the GABIE sampler. Bias was generally low and variability could be considered to be satisfactory (generally <20% with a maximum of 30% for ethylbenzene). For MEK, strong bias was noted together with probable underestimation of the tube results. Additional results lead us to suggest that this phenomenon could be due to poor desorption of the SKC tubes by carbon disulphide (CS₂); (quantitative recovery for MEK is in fact possible using other desorption solvents). Received: 23 December 1999 / Accepted: 26 July 2000     

Homozygous gene deletions of the glutathione S-transferases M1 and T1 are associated with thimerosal sensitization

Objective: Thimerosal is an important preservative in vaccines and ophthalmologic preparations. The substance is known to be a type IV sensitizing agent. High sensitization rates were observed in contact-allergic patients and in health care workers who had been exposed to thimerosal-preserved vaccines. There is evidence for the involvement of the glutathione system in the metabolism of thimerosal or its decomposition products (organomercury alkyl compounds). Thus detoxification by polymorphically expressed glutathione S-transferases such as GSTT1 and GSTM1 might have a protective effect against sensitization by these substances. Methods: To address this question, a case control study was conducted, including 91 Central European individuals with a positive patch-test reaction to thimerosal. This population was compared with 169 healthy controls and additionally with 114 individuals affected by an allergy against para-substituted aryl compounds. The latter population was included in order to test whether possible associations were due to substance-specific effects, or were a general feature connected with type IV immunological diseases. Homozygous deletions of GSTT1 and GSTM1 were determined by polymerase chain reaction. Results: Glutathione S-transferase M1 deficiency was significantly more frequent among patients sensitized to thimerosal (65.9%, P=0.013) compared with the healthy control group (49.1%) and the “para-compound” group (48%, P=0.034). Glutathione S-transferase T1 deficiency in the thimerosal/mercury group (19.8%) was barely elevated versus healthy controls (16.0%) and the “para-compound” group (14.0%). The combined deletion (GSTT1−/GSTM1−) was markedly more frequent among thimerosal-sensitized patients than in healthy controls (17.6% vs. 6.5%, P=0.0093) and in the “para-compound” group (17.6% vs. 6.1%, P=0.014), revealing a synergistic effect of these enzyme deficiencies (healthy controls vs. thimerosal GSTM1 negative individuals, OR=2.0 [CI=1.2–3.4], GSTT1−, OR=1.2 [CI=0.70–2.1], GSTM1/T1−, OR=3.1 [CI=1.4–6.5]). Conclusions: Since the glutathione-dependent system was repeatedly shown to be involved in the metabolism of thimerosal decomposition products, the observed association may be of functional relevance. Received: 8 September 1999 / Accepted: 25 March 2000     

Assessing Measurement Properties of Two Single-item General Health Measures

Background: Multi-item health status measures can be lengthy, expensive, and burdensome to collect. Single-item measures may be an alternative. We compared measurement properties of two single-item, general self-rated health (GSRH) questions to assess how well they captured information in a validated, multi-item instrument. Methods: We administered a general health survey (SF-12V) that included “standard” and “comparative” forms of a GSRH. We repeated the survey two weeks later to the same 75 medically stable outpatients to test for GSRH reproducibility, reliability, and validity using SF-12V Physical Functioning and Emotional Health subscales as a reference. Results: At each survey administration, the two GSRH questions demonstrated good alternate forms reliability (first administration: r=0.74, p<0.001; second administration: r=0.74, p<0.001) and good reproducibility (“standard”: ICC 0.69; “comparative”: ICC 0.85). Both GSRH items correlated with physical functioning (“standard”: r=0.66; “comparative”: r=0.56) and emotional health measures (“standard”: r=0.65; “comparative”: r=0.59). Mean subscale measures associated with responses in each GSRH category were significantly different (ANOVA, p<0.001), indicating strong discriminant scale performance. Conclusions: Our single-item, GSRH questions demonstrated good reproducibility, reliability, and strong concurrent and discriminant scale performance with an established health status measure.     

A Developmental Conceptualization of Return to Work

Introduction: Although return to work (RTW) is a phenomenon that has been researched for many years, our ability to understand and improve outcomes is still limited. As an avenue for advancing the field, this paper presents an alternative way of thinking about RTW. Method: The conceptualization was constructed based on a review of the literature and the comments of RTW and workers' compensation researchers. Results: RTW is presented as an evolving process, comprising four key phases: i.e., “off work,” “work re-entry,” “retention,” and “advancement.” In addition, multiple phase-specific outcomes that may be used to evaluate RTW success are advanced. Conclusion: Broadening thinking about RTW to take into consideration the complexities of its developmental nature holds promise for understanding and improving RTW, as it not only clarifies the importance of incremental milestones, but also facilitates intervention choice and evaluation.     

Analysis of Japanese occupational health services for small-scale enterprises, in comparison with the recommendations of the Joint WHO/ILO Task Group

Objectives: To evaluate Japanese occupational health services (OHSs) for small-scale enterprises (SSEs). Methods: The current Japanese OHSs for SSEs were compared with 15 recommendations of the Joint WHO/ILO Task Group. The status of OHSs was analyzed using the published papers collected by means of a computerized literature search. Thirty-five papers were used in the analysis, which was first conducted by the four authors separately, followed by discussion among the authors. Evaluation was conducted by classifying the status of Japanese OHSs for SSEs into three classes (A: good, B: average, C: poor) based on comparison with each recommendation. Results: Six issues were evaluated as “A”: establishment of a national policy for the provision of OHSs for SSEs, occupational health and safety inspection for SSEs, legislation to ensure services for SSEs and provision of financial incentives, adoption of occupational health programs using multiple channels, training in occupational health issues, and establishment of national data collection and registration systems. Nine issues were evaluated as “B”: provision of OHSs for all SSEs as a part of the “national Health for ALL” strategy, intervention combining economic development and OHSs, extension of OHSs to vulnerable groups, coverage of migrant and seasonal workers by OHSs, the establishment of a national collaborative and coordinative body on OHSs, control of transfer of hazardous technology, encouragement of applied research, employers' commitment and worker participation, and integration of OHSs with primary health care. None of them was evaluated as “C”. Conclusions: Japanese OHSs for SSEs were fairly well established in terms of compliance with the recommendations of the Joint WHO/ILO Task Group, although evaluation may be somewhat subjective and rather qualitative. Received: 08 September 1999 / Accepted: 31 January 2000     

Urinary N -acetyl-β-glucosaminidase as an indicator of renal dysfunction in electroplating workers

Objectives: To investigate chromium-induced renal dysfunction in electroplating workers. Methods: A cross-sectional study was used to evaluate four biochemical markers of renal function. A total of 178 workers were divided into 3 comparable groups consisting of 34 hard-chrome plating workers, 98 nickel-chrome electroplating workers, and 46 aluminum anode-oxidation workers, who represented the reference group. Ambient and biological monitoring of urinary chromium were performed to measure exposure concentrations. Results: Overall, urinary chromium concentrations were highest among hard-chrome plating workers (geometric mean 2.44 μg/g creatinine), followed by nickel-chrome electroplating workers (0.31 μg/g creatinine) and aluminum workers (0.09 μg/g creatinine). Airborne chromium concentrations were also highest in the hard-chrome plating area (geometric mean 4.20 μg/m³), followed by the nickel-chrome electroplating area (0.58 μg/m³) and the aluminum area (0.43 μg/m³). A positive correlation was found between urinary chromium and airborne concentrations (r = 0.54, P < 0.01). Urinary concentrations of N-acetyl-β-d-glucosaminidase (NAG) were also highest among hard-chrome plating workers (geometric mean 4.9 IU/g creatinine), followed by nickel-chrome workers (3.4 IU/g creatinine) and aluminum workers (2.9 IU/g creatinine). The prevalence of “elevated” NAG (>7 IU/g creatinine) was significantly highest among hard-chrome plating workers (23.5%), then among nickel-chrome workers (7.1%) and aluminum workers (8.7%). Differences in β₂-microglobulin, total protein, and microalbumin were not significant. Conclusion: The author's evidence indicates that NAG is an early indicator of renal dysfunction in hard-chrome plating workers.     

Inorganic fibres in the lung tissue of Hungarian and German lung cancer patients

Objective: To ascertain the lung burden of asbestos fibres in Hungarian lung cancer patients in comparison with the cumulative asbestos exposure estimated from the occupational history. Methods: For 25 Hungarian lung cancer patients, lung tissue fibre analysis was performed by scanning transmission electron microscopy (STEM) and counting of ferruginous bodies (FBs) by light microscopy. Cumulative asbestos exposure in fibre-years was assessed from a standardised occupational history using the report “fibre years” of the German Berufsgenossenschaften. Results: Median and maximum concentrations of fibres longer 5 μm per gram dry lung tissue (g dry) were 0.03 and 7.38 million fibres/g dry for chrysotile, 0.00 and 0.21 million fibres/g dry for amphibole and 0.22 and 0.62 million fibres/g dry for other mineral fibres (OMFs). The maximum values were observed in one patient for whom a high asbestos exposure was evident in advance from the occupational history. Conclusions: In comparison with reference values obtained by the same method for German patients with no indication of workplace asbestos exposure, increased concentrations of more than 0.2 million chrysotile fibres/g dry were obtained for six of the 25 Hungarian patients (24%). For one of them, the second highest estimate of a workplace exposure of 60 fibre-years and the highest tissue concentration of 7.38 million chrysotile fibres/g dry substantiate a high probability of a causal relationship to asbestos. A further comparison can be made with the results for 66 German patients treated by surgical lung resection for a disorder other than mesothelioma, mainly lung cancer. For the Hungarian lung cancer patients, similar amounts of chrysotile but distinctly lower amounts of amphibole fibres and distinctly higher amounts of OMFs were observed. A correlation between exposure estimates from occupational history and concentration of fibres in the lung tissue was observed for amphibole (Spearman: R=0.66, P < 0.001, Pearson: R=0.50, P=0.01) and for chrysotile (Pearson: R=0.48, P=0.02). Received: 3 May 2000 / Accepted: 14 September 2000     

Sexual Risk Behavior and Drug Use in Two Chicago Samples of Men Who Have Sex with Men: 1997 vs. 2002

Employing data from two Chicago-based household probability samples of men who have sex with men (MSM) implemented 5 years apart (the “UMHS 1997” and the “2002 MSM supplement” studies), we evaluated changes in risk behavior as well as the potential viability of two alternative perspectives for explaining these changes—risk management and safe-sex norm abandonment. We found significantly increased rates of unprotected insertive and receptive anal intercourse in the 2002 study. Sixty-eight percent of UMHS men reported having sex with partners having HIV positive or unknown status, compared with 38% of the MSM supplement men (p < .0001). Serosorting mediated and moderated the most extreme forms of risk behavior. Positive statistical associations between drug use and unprotected sex were stronger in the UMHS sample than in the MSM supplement. Findings suggesting that “risk management” strategies have shaped MSM behavior as it emerged in the early part of this decade have considerable implications for HIV prevention strategies.