Exposure to Particles and Nitrogen Dioxide Among Workers in the Stockholm Underground Train System.

OBJECTIVES: Exposure to fine particles in urban air has been associated with a number of negative health effects. High levels of fine particles have been detected at underground stations in big cities. We investigated the exposure conditions in four occupational groups in the Stockholm underground train system to identify high-exposed groups and study variations in exposure. METHODS: PM1 and PM2.5 were measured during three full work shifts on 44 underground workers. Fluctuations in exposure were monitored by a real-time particle monitoring instrument, pDR, DataRAM. Qualitative analysis of particle content was performed using inductively coupled plasma mass spectrometry. Nitrogen dioxide was measured using passive monitors. RESULTS: For all underground workers, the geometric mean (GM) of PM1 was 18 µg/m3 and of PM2.5 was 37 µg/m3. The particle exposure was highest for cleaners/platform workers, and the GM of PM1 was 31.6 µg/m3 [geometric standard deviation (GSD), 1.6] and of PM2.5 was 76.5 µg/m3 (GSD, 1.3); the particle exposure was lowest for ticket sellers, and the GM of PM1  was 4.9 µg/m3 (GSD, 2.1) and of PM2.5 was 9.3 µg/m3 (GSD, 1.5). The PM1 and PM2.5 levels were five times higher in the underground system than at the street level, and the particles in the underground had high iron content. The train driver's nitrogen dioxide exposure level was 64.1 µg/m3 (GSD, 1.5). CONCLUSIONS: Cleaners and other platform workers were statistically significantly more exposed to particles than train drivers or ticket sellers. Particle concentrations (PM2.5) in the Stockholm underground system were within the same range as in the New York underground system but were much lower than in several older underground systems around the world.

Is skin exposure to water mainly occupational or nonoccupational? A population-based study.

BACKGROUND: Skin exposure to water is considered to contribute to hand eczema. Knowledge about total water exposure during a day is scanty. OBJECTIVES: To investigate self-reported water exposure at work as well as throughout the day. METHODS: Skin exposure to water was assessed from two questionnaire-based health surveys: the nationwide Environmental Health Survey 2007 (EHS), which enquired about water exposure throughout the day, and the Stockholm Public Health Survey 2006 (PHS), which probed water exposure at work. Answers from 19,667 individuals (EHS) and 18,318 individuals (PHS) were available for analysis. RESULTS: In total, 22% of respondents (women 30%, men 12%) reported skin exposure to water more than 20 times during an entire day (EHS) compared with 6% (women 8%, men 4%) at work (PHS). In a univariate analysis, using a merged file comprising data from the EHS and the PHS, water exposure more than 20 times a day was more common in the EHS (prevalence proportion ratio 3·570, 95% confidence interval 3·353-3·802). In multivariate models the variables studied did not fulfil the criteria for being confounders. Water exposure at work declined with increasing age in both women and men (P < 0·0001) as did water exposure during the entire day in men (P < 0·0001). However, women were equally exposed during the entire day across age groups (P = 0·205). CONCLUSIONS: High water exposure over the entire day was found to be considerably more frequent than exposure at work. Thus, a significant proportion of water exposure seems to occur outside work. This should be considered in prevention of hand eczema and when counselling patients with hand eczema in clinical practice.

Life-style factors and hand eczema.

BACKGROUND: Previous knowledge of the impact of certain life-style factors on hand eczema is scanty. OBJECTIVES: To investigate a possible association between hand eczema and life-style factors such as obesity, physical exercise, stress, smoking and alcohol consumption. METHODS: In a cross-sectional public health survey in Stockholm, Sweden, 27,994 (58%) randomly chosen individuals aged 18-64 years completed a postal questionnaire regarding physical and mental health, social relations, economic status and work. Of these, 27,793 individuals responded to the question regarding hand eczema and were included in the present study. The association between life-style factors and hand eczema was analysed by prevalence proportion ratios (PPR), using a generalized linear model. RESULTS: Hand eczema was more common among individuals who reported high stress levels, PPR 1·326 (95% CI 1·303-1·350). There was also a positive dose-response relationship between hand eczema and stress. Hand eczema was less common among individuals reporting high physical exercise, and most apparent in women, PPR 0·781 (95% CI 0·770-0·792). Men who reported high alcohol intake reported hand eczema less often, PPR 0·958 (95% CI 0·930-0·987). Obese individuals reported hand eczema more commonly, PPR 1·204 (95% CI 1·174-1·234). There was a slight increase of hand eczema among smokers, PPR 1·025 (95% CI 1·006-1·044). CONCLUSIONS: Hand eczema was more common in individuals who reported stress, obesity and smoking. In individuals who reported high physical exercise levels hand eczema was less common. As there appears to be an association between life-style factors and hand eczema it is important to consider life-style factors in clinical practice.

Tobacco smoking and hand eczema: a population-based study.

BACKGROUND: Tobacco smoking has been proposed to promote hand eczema. OBJECTIVES: To examine the association between tobacco smoking and hand eczema and to investigate a possible dose-response relation. METHODS: A national environmental health survey was performed in 2007. A questionnaire was mailed to 43,905 individuals and responses were obtained from 25,851 (59%). Questions on 1-year prevalence of hand eczema and on previous and current smoking were included. Respondents were asked to report number of cigarettes per day and to provide information on history of atopy and frequency of hand exposure to water. RESULTS: In total, answers regarding smoking and hand eczema were obtained from 25,428 individuals. Of regular daily smokers, 10·0% reported hand eczema vs. 9·1% of nonsmokers (P = 0·0951). A history of atopy showed the strongest influence on the occurrence of hand eczema: prevalence proportion ratio (PPR) 3·46. The PPR for hand eczema among individuals smoking > 15 cigarettes per day was 1·25 and 1·40 in uni- and multivariate analysis, respectively. Age, history of atopy, sex and water exposure were found to be confounders but not effect modifiers. A dose-response relation between level of smoking and 1-year prevalence of hand eczema was revealed with a PPR of 1·05 (P < 0·001) for the continuous variable of smoking habits, indicating a significantly increased prevalence of hand eczema among individuals with higher consumption of tobacco. CONCLUSIONS: An association between heavy smoking and hand eczema was confirmed. It is important to consider the level of exposure, as a dose-response relation was revealed, and to be aware of confounding factors.

Hand eczema and quality of life: a population-based study.

BACKGROUND: Hand eczema is a common disease in the population and is of interest from a public health perspective. Health-related quality of life (HRQoL) is increasingly being measured in dermatology. OBJECTIVES: To investigate HRQoL in relation to hand eczema in the general population. METHODS: In the Public Health Survey of Stockholm County Council 2006, a questionnaire was sent to 57 009 randomly selected individuals aged 18-84 years. The response rate among persons of working age (18-64 years) was 58%. The questionnaire included a validated question concerning hand eczema and a generic instrument for measurement of HRQoL, the EQ-5D. RESULTS: The proportion of individuals reporting problems was significantly larger among those with than without hand eczema in all five dimensions of the EQ-5D. Gender differences were found in some age subgroups. The EQ-5D index was lower for individuals with hand eczema than for those without, and on the same level as for psoriasis and asthma. Beta regression showed that the strongest confounding factors were low back pain, depression and hay fever/asthma. CONCLUSIONS: HRQoL was negatively affected in individuals with hand eczema irrespective of age. With the EQ-5D instrument it is also possible to detect certain gender differences. The EQ-5D index for hand eczema was of the same size as for psoriasis and asthma, all common diseases with an impact on public health. It is of importance to acknowledge the influence of hand eczema on daily life, in order to give the patients good care.

Occupational skin exposure to water: a population-based study.

BACKGROUND: Occupational exposure to skin irritants, in particular to water, is an important risk factor for hand eczema. OBJECTIVES: To assess occupational skin exposure to water in the general population. METHODS: As part of a public health survey in Stockholm, Sweden, 18,267 gainfully employed individuals aged 18-64 years completed a questionnaire with previously validated questions regarding occupational skin exposure to water. RESULTS: Altogether 16% reported exposure to water for (1/2) h or more a day, and 13% reported exposure to water more than 10 times a day. Furthermore, 7% reported water exposure of more than 2 h and 6% of more than 20 times a day. Women reported more water exposure than men and many female-dominated occupations were seen to comprise water exposure. Women were also more exposed than men within the same jobs. Young adults were more exposed than older. A total of 18% were employed in high-risk occupations for hand eczema. Fifty-nine per cent of individuals employed in high-risk occupations reported water exposure at work, compared with 11% in low-risk occupations. CONCLUSIONS: A total of 20% of the population of working age acknowledged occupational skin exposure to water, which was found to be more common in young adults and women. Using job title as a proxy for water exposure gives an underestimation due to misclassification. In assessing occupational skin exposure to water, both exposure time and frequency should be considered.

Does tobacco smoking influence the occurrence of hand eczema?

BACKGROUND: Tobacco smoking is known to influence various inflammatory skin diseases and an association between tobacco smoking and hand eczema has been proposed in some studies. OBJECTIVES: To examine a possible association between reported current tobacco smoking and the occurrence of hand eczema. SUBJECTS AND METHODS: Previously collected questionnaire data on the occurrence of hand eczema in three occupational cohorts and corresponding controls from the general population were studied. The questionnaires used included questions on 1-year prevalence of hand eczema and questions on smoking habits. For one occupational group, hairdressers and their controls, information on amount of smoking was obtained. Information on age, sex and history of atopy was also available. RESULTS: In total, answers regarding smoking and hand eczema were obtained from 13,452 individuals. Out of 3493 smokers, 437 (12.5%) reported hand eczema compared with 1294 out of 9959 nonsmokers (13.0%) (P = 0.51). With regard to the number of cigarettes smoked, 22.6% of the hairdressers smoking more than 10 cigarettes per day reported hand eczema compared with 17.4% of those smoking 0-10 cigarettes per day (P = 0.01). Corresponding figures for the controls were 14.5% and 11.7%, respectively (P = 0.06). CONCLUSIONS: No clear association was found between 1-year prevalence of hand eczema and smoking. Heavy smoking, more than 10 cigarettes per day, may give a slightly increased risk of hand eczema. Further studies with information on the amount of tobacco consumption and on possible confounders are needed to evaluate smoking as a risk factor for hand eczema.

Blood markers of inflammation and coagulation and exposure to airborne particles in employees in the Stockholm underground.

OBJECTIVES: Although associations have been found between levels of ambient airborne particles and cardiovascular disease (CVD) in the general population, little is known about possible cardiovascular effects from high exposure to particles in underground railway systems. This study investigates risk markers for CVD in employees exposed to particles in the Stockholm underground system. METHODS: 79 workers (54 men and 25 women) in the Stockholm underground were investigated between November 2004 and March 2005. All were non-smokers aged 25-50 years. Three exposure groups were delineated: 29 platform workers with high exposure to particles, 29 train drivers with medium exposure and 21 ticket sellers with low exposure (control group). A baseline blood sample was taken after 2 non-working days, and a second sample after 2 working days, for analysis of levels of plasminogen activator inhibitor-1 (PAI-1), high-sensitivity C-reactive protein (hs-CRP), interleukin-6, fibrinogen, von Willebrand factor and factor VII. The study investigated changes in plasma concentrations between sample 1 and sample 2, and differences in average concentrations between the groups. RESULTS: No changes between sample 1 and 2 were found that could be attributed to particle exposure. However, the highly exposed platform workers were found to have higher plasma concentrations of PAI-1 and hs-CRP than the ticket sellers and train drivers. This suggests that particle exposure could have a long-term inflammatory effect. These differences remained for PAI-1 in the comparison between platform workers and ticket sellers after adjusting for body mass index. CONCLUSIONS: Employees who were highly exposed to airborne particles in the Stockholm underground tended to have elevated levels of risk markers for CVD relative to employees with low exposure. However, the differences observed cannot definitely be linked to particle exposure as such.