Incidence of hand eczema in female Swedish hairdressers

Objective

To estimate the occurrence of hand eczema in hairdressers in Sweden.

Methods

The occurrence of hand eczema was estimated in a Swedish longitudinal retrospective cohort study including all female graduates from vocational schools for hairdressers from 1970 to 1995. A stratified sample from the general population acted as controls. A self‐administered questionnaire including questions on the occurrence of hand eczema, skin atopy, working periods and number of hair treatments performed per week was sent to the participants. Incidence rate ratios (IRRs) of hand eczema were estimated.

Results

The incidence rate of hand eczema in hairdressers was 23.8 cases/1000 person‐years, whereas in hairdressers who were aged <25 years it was 37.1/1000 person‐years. The corresponding IRR for hairdressers compared with controls was 2.5 (95% confidence interval (CI) 2.2 to 2.8), and that for younger hairdressers was 3.1 (95% CI 2.6 to 3.5). The mean age at onset of hand eczema was 21.6 years for hairdressers and 21.2 years for controls. The 1‐year prevalence of hand eczema was 18.0% for hairdressers and 12.1% for controls. A large number of hair treatments involving exposure to skin irritants and sensitisers were reported. The incidence rate of hand eczema was higher among individuals with a history of childhood eczema, both for hairdressers and for controls, giving an (age‐adjusted) IRR of 1.9 and 2.2, respectively. The attributable fraction of hand eczema from skin atopy was 9.6%. A synergistic effect of skin atopy and hairdressing was found on the occurrence of hand eczema. The relative excess risk due to interaction was 1.21 (95% CI 0.21 to 2.21; p = 0.01).

Conclusion

Hairdressers are highly exposed to skin‐damaging substances. The self‐reported incidence of hand eczema was substantially higher in female hairdressers than in controls from the general population and than that found previously in register‐based studies. For many individuals, onset of hand eczema occurs early in life. Only about 10% of the hand eczema cases among hairdressers would be prevented if no one with skin atopy entered the trade.There are about 19 000 hairdressers in Sweden, of whom 80–90% are women and most are self‐employed, working in small salons. Hand eczema is a well‐known problem in occupations that involve largely manual work, particularly in combination with long periods of wet exposure and skin contact with chemicals. Hairdressing includes extensive wet work, which can cause irritant contact dermatitis. Many hair cosmetics such as hair colourings, permanent wave solutions and bleaches can also cause contact allergy. Previous studies on the occurrence of hand eczema in hairdressers give a cumulative prevalence of 17–42%.^1,2 A high prevalence (24–70%) and incidence rate (152–328 cases/1000 person‐years) of hand eczema have been found among apprentice hairdressers.^3,4,5 The only studies presenting incident rates of hand eczema in active hairdressers are based on registers of industrial injuries, which report incidences of 5.6–9.7/1 000 person‐years.^6,7 Registers of occupational skin diseases probably underestimate the actual occurrence of disease owing to under‐reporting.⁸ The objective of this study was to estimate the incidence of hand eczema and occupational skin exposure in female hairdressers using a self‐administered questionnaire.     

Characteristics of work related asthma: results from a population based survey

Objectives

Many risk factors for asthma have been investigated, one of which is the workplace. Work related asthma is a frequently reported occupational respiratory disease yet the characteristics which distinguish it from non‐work related asthma are not well understood. The purpose of this study was to examine differences between work related and non‐work related asthma with respect to healthcare use and asthma control characteristics.

Methods

Data from the Massachusetts Behavioral Risk Factor Surveillance System for 2001 and 2002 were used for this analysis. Work related status of asthma was determined by self‐report of ever having been told by a physician that asthma was work related. Healthcare measures evaluated were emergency room visits and physician visits for worsening asthma and for routine care. Characteristics of asthma control evaluated were frequency of asthma symptoms, asthma attacks, difficulty sleeping, and asthma medication usage in the last 30 days and limited activity in the past 12 months.

Results

The prevalence of lifetime and current asthma in Massachusetts were 13.0% and 9.2%, respectively. Approximately 6.0% (95% CI 4.8 to 7.3) of lifetime and 6.2% (95% CI 4.7 to 7.8) of current asthma cases were work related. In the past 12 months, individuals with work related current asthma were 4.8 times (95% CI 2.0 to 11.6) as likely to report having an asthma attack, 4.8 times (95% CI 1.8 to 13.1) as likely to visit the emergency room at least once, and 2.5 times (95% CI 1.1 to 6.0) as likely to visit the doctor at least once for worsening asthma compared to individuals with non‐work related asthma.

Conclusions

Work related asthma is associated with increased frequency of asthma attacks and use of healthcare services. A better understanding of factors that contribute to differences in healthcare use and asthma control is needed to improve prevention and control strategies for individuals suffering from the disease.     

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.     

Validation of an asthma questionnaire for use in healthcare workers

Background

Previous studies have described increased occurrence of asthma among healthcare workers, but to our knowledge there are no validated survey questionnaires with which to study this occupational group.

Aims

To develop, validate, and refine a new survey instrument on asthma for use in epidemiological studies of healthcare workers.

Methods

An initial draft questionnaire, designed by a multidisciplinary team, used previously validated questions where possible; the occupational exposure section was developed by updating health services specific chemical lists through hospital walk‐through surveys and review of material safety data sheets. A cross‐sectional validation study was conducted in 118 non‐smoking subjects, who also underwent bronchial challenge testing, an interview with an industrial hygienist, and measurement of specific IgE antibodies to common aeroallergens.

Results

The final version consisted of 43 main questions in four sections. Time to completion of the questionnaire ranged from 13 to 25 minutes. Test–retest reliability of asthma and allergy items ranged from 75% to 94%, and internal consistency for these items was excellent (Cronbach''s α ⩾ 0.86). Against methacholine challenge, an eight item combination of asthma related symptoms had a sensitivity of 71% and specificity of 70%; against a physician diagnosis of asthma, this same combination showed a sensitivity of 79% and specificity of 98%. Agreement between self‐reported exposures and industrial hygienist review was similar to previous studies and only moderate, indicating the need to incorporate more reliable methods of exposure assessment. Against the aerollergen panel, the best combinations of sensitivity and specificity were obtained for a history of allergies to dust, dust mite, and animals.

Conclusions

Initial evaluation of this new questionnaire indicates good validity and reliability, and further field testing and cross‐validation in a larger healthcare worker population is in progress. The need for development of more reliable occupational exposure assessment methods that go beyond self‐report is underscored.     

Employment status and use of respiratory protection among metalworkers, solderers and welders

Objectives

Reported associations of self‐employment with occupational injury and cerebrovascular disease suggest that worker safety and health precautions may vary by occupational status. The authors assessed the extent to which use of respiratory protection and ventilation equipment is associated with self‐employed versus employee status among adults in an international study.

Methods

The European Community Respiratory Health Survey II (ECRHS II) is a follow‐up study conducted in a population‐based random sample of adult ECRHS I participants. Men and women enrolled in the ECRHS II completed interviewer‐administered questionnaires to provide information about their occupational status and job history during the 9‐year ECRHS follow‐up period. Respondents in selected occupational groups completed supplemental questionnaires about their jobs and use of respiratory protection and ventilation equipment on‐the‐job. The authors assessed self‐reported use of respiratory and ventilation equipment among 72 self‐employed and 371 employed adults in metalworking, soldering and welding occupations.

Results

Local exhaust ventilation (fixed extraction: OR 0.37, 95% CI 0.17 to 0.80; mobile extraction: OR 0.23, 95% CI 0.09 to 0.60; on‐tool extraction: OR 0.39, 95% CI 0.18 to 0.88) was reported less frequently among self‐employed respondents than among employed respondents. The magnitude of the negative association between self‐employment status and any of the three types of local exhaust ventilation was not attenuated by adjustment for duration of work per day or week or asthma and/or wheezing symptoms. Respiratory protection was not associated with employment status in these data.

Conclusions

More limited use of local exhaust ventilation among self‐employed workers compared to employees suggests the need to promote occupational safety among self‐employed workers.Information about the working conditions of employees may not reflect the experiences of self‐employed individuals working in the same fields. Self‐employed people who work independently or operate their own businesses may take advantage of the increased autonomy often associated with self‐employment to organise their work schedules and practices to more closely suit their professional preferences. In many industries, self‐employed workers have the opportunity to select their own hours, work settings, clients and equipment. Workers with this degree of flexibility may develop their own occupational health and safety practices, but existing information describing the working conditions of self‐employed individuals is insufficient to indicate how practices differ from those of employees, or how these differences affect health and safety.Recent research provides evidence that health and safety precautions and job training vary between workers in self‐employed and employed work situations.¹ Results from a 2005 survey conducted in the EU indicate that self‐employed workers experienced greater autonomy and less violence, harassment and/or discrimination on the job and had fewer days of health‐related absence over the past year compared to employed respondents. In contrast, the self‐employed respondents more frequently reported that they considered their health and safety to be at risk because of work and a slightly smaller percentage reported wearing personal protective clothing or equipment at work (self‐employed 29% vs employed 35%).¹ Although the survey did not include industry‐ or job‐specific estimates or health outcomes related to the use of personal protective equipment, overall these responses reveal some of the reasons individuals may seek self‐employment situations, and raise the possibility that self‐employed work arrangements may result in important health and safety risks.Previous research has shown differences in the rates of work‐related mortality among the self‐employed and privately‐employed populations.^2,3 For example, using data reported through a medical examiner''s surveillance system, notably higher fatal occupational injury rates were observed among self‐employed workers in the agricultural sector and in retail and transportation industries.² The surveillance‐based study found lower rates among self‐employed workers in the construction industry, suggesting differences in the occupational health and safety practices of self‐employed and employed individuals.² Such variations in the rates of occupational injury may reflect differences in work‐related tasks, settings, use of protective equipment or differences in the age and/or levels of work experience between the two populations. In contrast, lower rates of cerebrovascular disease have been reported among self‐employed men than among employed men. Although the differences were not observed for overall mortality or other circulatory disorders, the investigators concluded that the effect of self‐employment status was independent of those associated with other lifestyle and medical factors and thus may be considered an additional determinant of health.⁴ Differences in mortality rates between self‐employed and employed populations led the investigators to suggest considering employment status as a proxy for differences in working practices, including the physical work environment.Despite these observed differences in occupational practices, mortality and cardiovascular morbidity, occupational health and safety practices of self‐employed workers remain largely unreported in the public health literature. For this analysis, we investigated a hypothesis for which there is little epidemiological evidence—that is, whether employment status is associated with use of respiratory protection and/or ventilation equipment. We used data from the European Community Respiratory Health Survey (ECRHS), a population‐based cohort of adult men and women, to examine self‐reported use of respiratory protection and ventilation equipment among self‐employed and employed respondents.     

How consistently distributed are the socioeconomic differences in severe back morbidity by age and gender? A population based study of hospitalisation among Finnish employees

Aims

To study the socioeconomic distribution of severe back morbidity by age and gender, and to examine to what extent the differences in back morbidity between socioeconomic groups are particularly related to manual work in different age groups.

Methods

Hospital admissions in 1996 for back disorders of 25–64 year old men (3123 of a total 743 961) and women (3043 of 773 936) from the Finnish Hospital Discharge Register were linked with demographic and socioeconomic data from the 1995 population census. Poisson regression analysis was used to calculate the rate ratios for back related hospitalisation by occupational class and education. The distribution of cases according to occupational status and education was presented in relation to the whole occupationally active workforce by age and gender.

Results

Blue‐collar (manual) workers had a higher risk of being hospitalised because of back disorders compared with white‐collar employees (non‐manual) in all age groups among both genders. Manual work versus non‐manual work was associated with a 1.3 to 1.4‐fold risk (95% CI 1.0 to 1.8) among women and a 1.3 to 1.6‐fold risk (95% CI 1.1 to 2.2) among men. The risk of hospitalisation was further inversely associated with educational level within manual and non‐manual work in all other age groups except in those aged 55–64 years. Gender related differences were much smaller compared with the socioeconomic ones.

Conclusions

Socioeconomic differences in back morbidity leading to hospitalisation were consistent by age and gender. The results suggest that not only the physical strenuousness of work, but also other causes of severe back disorders are clustered around a subject''s socioeconomic status, indicated by formal education. This may have implications for prevention and the planning of rehabilitation.     

Leukaemia, brain tumours and exposure to extremely low frequency magnetic fields: cohort study of Swiss railway employees

Aims

To investigate the relationship between extremely low frequency magnetic field (ELF‐MF) exposure and mortality from leukaemia and brain tumour in a cohort of Swiss railway workers.

Methods

20 141 Swiss railway employees with 464 129 person‐years of follow‐up between 1972 and 2002 were studied. Mortality rates for leukaemia and brain tumour of highly exposed train drivers (21 μT average annual exposure) were compared with medium and low exposed occupational groups (i.e. station masters with an average exposure of 1 μT). In addition, individual cumulative exposure was calculated from on‐site measurements and modelling of past exposures.

Results

The hazard ratio (HR) for leukaemia mortality of train drivers was 1.43 (95% CI 0.74 to 2.77) compared with station masters. For myeloid leukaemia the HR of train drivers was 4.74 (95% CI 1.04 to 21.60) and for Hodgkin''s disease 3.29 (95% CI 0.69 to 15.63). Lymphoid leukaemia, non‐Hodgkin''s disease and brain tumour mortality were not associated with magnetic field exposure. Concordant results were obtained from analyses based on individual cumulative exposure.

Conclusions

Some evidence of an exposure–response association was found for myeloid leukaemia and Hodgkin''s disease, but not for other haematopoietic and lymphatic malignancies and brain tumours.     

Maternal and paternal occupational exposure to agricultural work and the risk of anencephaly

Aims

To evaluate the association between parental occupational exposure to agricultural work and the risk of anencephaly in three Mexican states.

Methods

A paired case control study (1:1) was done based on records of the Epidemiological Surveillance System of Neural Tube Defects in Mexico; 151 cases of anencephaly of more than 20 weeks'' gestation were selected between March 2000 and February 2001. Controls were selected from the same maternity services as those of the cases and were born alive without congenital malformations. Information was obtained from both parents by means of a general questionnaire, a food frequency questionnaire, and a specific questionnaire on occupational exposure to pesticides. Exposures were analysed with emphasis on the three months before and one month after the last menstruation periods (acute risk period (ARP)), as well as exposure prior to the abovementioned period (non‐acute risk period (NARP)).

Results

The children of mothers who worked in agriculture in the ARP had a greater risk of anencephaly (OR = 4.57, 95% CI 1.05 to 19.96). The risk of fathers having a child with anencephaly was greater in those who applied pesticides irrespective of whether it was done in the ARP or the NARP (OR = 2.50, 95% CI 0.73 to 8.64; and OR = 2.03, 95% CI 0.58 to 7.08, respectively).

Conclusions

These results support the hypothesis of the effect of maternal exposure to agricultural work on anencephaly and suggest that exposure of the father to pesticides in the periconceptional period or prior to this can also increase the risk of having an anencephalic child.     

Lifetime occupation and physical function: a prospective cohort study on persons aged 80 years and older living in a community

Background

Several studies have reported predictors for loss of mobility and impairments of physical performance among frail elderly people.

Aim

To evaluate the relationship between lifetime occupation and physical function in persons aged 80 years or older.

Methods

Data are from baseline evaluation of 364 subjects enrolled in the ilSIRENTE study (a prospective cohort study performed in a mountain community in Central Italy). Physical performance was assessed using the physical performance battery score, which is based on three timed tests: 4‐metre walking speed, balance, and chair stand tests. Muscle strength was measured by hand grip strength. Lifetime occupation was categorised as manual or non‐manual work.

Results

Mean age of participants was 85.9 (SD 4.9) years. Of the total sample, 273 subjects (75%) had a history of manual work and 91 subjects (25%) a history of non‐manual work. Manual workers had significant lower grip strength and physical performance battery score (indicating worse performance) than non‐manual workers. After adjustment for potential confounders (including age, gender, education, depression, cognitive performance scale score, physical activity, number of diseases, hearing impairment, history of alcohol abuse, smoking habit, and haemoglobin level), manual workers had significantly worse physical function (hand grip strength: non‐manual workers 32.5 kg, SE 1.4, manual workers 28.2 kg, SE 0.8; physical performance battery score: non‐manual workers 7.1, SE 0.4, manual workers 6.1, SE 0.2).

Conclusions

A history of manual work, especially when associated with high physical stress, is independently associated with low physical function and muscle strength in older persons.     

Self-reported health problems and sickness absence in different age groups predominantly engaged in physical work

Objectives

To study the associations between self‐reported health problems and sickness absence from work.

Methods

The results of a questionnaire survey were combined with archival data of sickness absence of 1341 employees (88% males; 62% blue‐collar) in the construction, service and maintenance work within one corporation in Finland. Sex, age and occupational grading were controlled as confounders. A zero‐inflated negative binomial (ZINB) regression model was used in the statistical analysis of sickness absence data.

Results

The prevalence of self‐reported health problems increased with age, from 23% in 18–30‐year‐olds to 54% in 55–61‐year‐olds. However, in those aged 18–30 years, 71% had been absent from work and in those aged 55–61 years this proportion was 53%. When health problems and occupational grading were accounted for in the ZINB model, age as such was not associated with the number of days on sick leave, but the young workers still had higher propensity for (any) sickness absence than the old. Self‐rated future working ability and musculoskeletal impairment were strong determinants of sickness absence. Among those susceptible to taking sick leave, the estimated mean number of absence days increased by 14% for each rise of 1 unit of the impairment score (scale 0–10).

Conclusions

Young subjects had surprisingly high probability for sickness absence although they reported better health than their older colleagues. A higher total count of absence days was found among subjects reporting health problems and poorer working ability, regardless of age, sex and occupational grade. These findings have implications for both management and the healthcare system in the prevention of work disability.Sickness absence means non‐attendance by an employee at work due to a (certified) health complaint when the employer expects attendance. Despite the straightforward definition, sickness absence has proved to be a complex phenomenon. In addition to illness, it has been associated with, for example, demographical and socioeconomic factors, organisational features, job content and attitudes to work.¹ The key psychosocial predictors of sickness absence include individuals'' own perceptions of health and working ability.^2,3It is a common belief that older (supposedly in poorer health) employees are more absent from work than their younger (supposedly healthier) colleagues.^4,5 However, the young seem to stay out of work due to minor health complaints more than older workers. Also some earlier studies have found that older age increases the risk of overall sickness absences, but decreases that of one‐day absences.⁶We investigated how age and self‐reported health problems are associated with sickness absence within a cohort predominantly employed in physical work.     

Association of ventricular arrhythmias detected by implantable cardioverter defibrillator and ambient air pollutants in the St Louis, Missouri metropolitan area

Background

It has previously been reported that the risk of ventricular arrhythmias is positively associated with ambient air pollution among patients with implantable cardioverter defibrillators (ICD) in Boston.

Aims

To assess the association of community exposures to air pollution with ventricular arrhythmias in a cohort of ICD patients in metropolitan St Louis, Missouri.

Methods

ICD detected episodes reported during clinical follow up were abstracted and reviewed by an electrophysiologist to identify ventricular arrhythmias. A total of 139 ventricular arrhythmias were identified among 56 patients. A case‐crossover design was used with control periods matched on weekday and hour of the day within the same calendar month. Conditional logistic regression models were adjusted for temperature, barometric pressure, and relative humidity in the 24 hours preceding the event.

Results

There was a significant (24%, 95% CI 7% to 44%) increase in risk of ventricular arrhythmias associated with each 5 ppb increase in mean sulphur dioxide and non‐significantly increased risk (22%, 95% CI −6% to 60%; and 18%, 95% CI −7% to 50%) associated with increases in nitrogen dioxide (6 ppb) and elemental carbon (0.5 μg/m³), respectively in the 24 hours before the arrhythmia.

Conclusions

These results provide evidence of an association between ventricular arrhythmias and ambient air pollutants in St Louis. This is consistent with previous results from Boston, although the pollutants responsible for the increased risk are different.     

Assigning exposure to pesticides and solvents from self-reports collected by a computer assisted personal interview and expert assessment of job codes: the UK Adult Brain Tumour Study

Objectives

To compare assignment of occupational pesticide and solvent exposure using self‐reported data collected by a computer assisted personal interview (CAPI) with exposure based on expert assessment of job codes. To discuss the advantages and disadvantages of using a CAPI to collect individual occupational exposure data.

Methods

Between 2001 and 2004, 1495 participants were interviewed using a CAPI for a case‐control study of adult brain tumours and acoustic neuromas. Two types of occupational data were collected: (1) a full history, including job title from which a job code was assigned from the Standard Occupational Classification; and (2) specific details on pesticide and solvent exposure reported by participants. Study members'' experiences of using the CAPI were recorded and advantages and disadvantages summarised.

Results

Of 7192 jobs recorded, the prevalence of self‐reported exposure was 1.3% for pesticides and 11.5% for solvents. Comparing this with exposure expertly assessed from job titles showed 53.6% and 45.8% concordance for pesticides and solvents respectively. Advantages of the CAPI include no data entry stage, automatic input validation, and a reduction in interviewer bias. Disadvantages include an adverse effect on study implementation as a consequence of resources required for programming and difficulties encountered with data management prior to analysis.

Conclusions

Different methods of exposure assessment derive different exposure levels for pesticide and solvent exposure at work. Agreement between self‐reported and expert assessment of exposure was greater for pesticides compared to solvents. The advantages of using a CAPI for the collection of complex data outweigh the disadvantages for interviewers and data quality but using such a method requires extra resources at the study outset.     

Long hours in paid and domestic work and subsequent sickness absence: does control over daily working hours matter?

Objectives

To explore the associations of working hours (paid, domestic, commuting, and total) with sickness absence, and to examine whether these associations vary according to the level of employee control over daily working hours.

Methods

Prospective cohort study among 25 703 full‐time public sector employees in 10 towns in Finland. A survey of working hours and control over working hours was carried out in 2000–01. The survey responses were linked with register data on the number of self‐certified (⩽3 days) and medically certified (>3 days) sickness absences until the end of 2003. Poisson regression analyses with generalised estimating equations were used to take into account the fact that the employees were nested within work units. Adjustments were made for work and family characteristics and health behaviour. The mean follow‐up period was 28.1 (SD 8.1) months.

Results

Long domestic and total working hours were associated with higher rates of medically certified sickness absences among both genders. In contrast, long paid working hours were associated with lower rates of subsequent self‐certified sickness absences. Long commuting hours were related to increased rates of sickness absence of both types. Low control over daily working hours predicted medically certified sickness absences for both the women and men and self‐certified absences for the men. In combinations, high control over working hours reduced the adverse associations of long domestic and total working hours with medically certified absences.

Conclusions

Employee control over daily working hours may protect health and help workers successfully combine a full‐time job with the demands of domestic work.     

Assessment of lifetime exposure to trihalomethanes through different routes

Objectives

To evaluate lifetime exposure to trihalomethanes (THM) through ingestion, inhalation, and dermal absorption in a hospital based case‐control study of bladder cancer conducted between 1998 and 2001 in five areas of Spain. The study base was comprised of subjects living in the catchment areas of the participating hospitals.

Methods

Individual information on water related habits was obtained from personal interviews of 1219 cases and 1271 controls: residential and occupational history, drinking water source at each residence and job, amount of water consumption, frequency and duration of showering, bathing, and swimming pool attendance. THM levels, water source history, and year when chlorination started in study areas were ascertained through measurements in drinking water samples and questionnaires to water companies and local authorities. Estimates of THM levels covered 79% of the subjects'' person‐years of exposure.

Results

Current and historical average THM levels in water were correlated. Control subjects reported that drinking water source in the last residence was municipal for 63%, bottled for 22%, private well for 2%, and other sources for 13%. For the time window between age 15 and the time of interview, average residential THM level was 32.2 μg/l. THM exposure through ingestion was 23.7 μg/day on average, and was correlated with the ingestion THM level in the workplace. Overall, 79% usually took showers, 16% usually took baths, and 13% had ever attended a swimming pool. Between 21% and 45% of controls unexposed to THM through ingestion were evaluated as moderately or highly exposed through showering or bathing, and 5–10% were exposed through swimming in pools.

Conclusion

The importance of evaluating different routes is underscored by findings from experimental studies showing substantial differences in THM uptake and internal distribution by route.     

Occupational exposure to power frequency magnetic fields and risk of non-Hodgkin lymphoma

Objectives

To investigate the risk of non‐Hodgkin lymphoma (NHL) using a job‐exposure matrix (JEM) to assess exposure to occupational magnetic fields at the power frequencies of 50/60 Hz.

Methods

The study population consisted of 694 cases of NHL, first diagnosed between 1 January 2000 and 31 August 2001, and 694 controls from two regions in Australia, matched by age, sex and region of residence. A detailed occupational history was given by each subject. Exposure to power frequency magnetic fields was estimated using a population‐based JEM which was specifically developed in the United States to assess occupational magnetic field exposure. The cumulative exposure distribution was divided into quartiles and adjusted odds ratios were calculated using the lowest quartile as the referent group.

Results

For the total work history, the odds ratio (OR) for workers in the upper quartile of exposure was 1.48 (95% CI 1.02 to 2.16) compared to the referent (p value for trend was 0.006). When the exposure was lagged by 5 years the OR was 1.59 (95% CI 1.07 to 2.36) (p value for trend was 0.003). Adjusting for other occupational exposures did not significantly alter the results.

Conclusions

These findings provide weak support for the hypothesis that occupational exposure to 50/60 Hz magnetic fields increases the risk of NHL.     

Medical downgrading, self-perception of health, and psychological symptoms in the British Armed Forces

Objective

To investigate the contribution of psychological symptoms to limited employability for medical reasons in the British Armed Forces.

Methods

A sample of 4500 military personnel was randomly selected to receive either a full or an abridged questionnaire. The questionnaires asked whether the participant was medically downgraded and if yes, the reason for it. The full questionnaire included the General Health Questionnaire‐12 (GHQ‐12), the post‐traumatic stress disorder (PTSD) checklist, 15 symptoms to assess somatisation, and selected items of the quality of life SF‐36 questionnaire. The abridged questionnaire included the GHQ‐4, a 14 item PTSD checklist, five symptoms, and the item on self‐perception of health from the SF‐36. Subjects above a threshold score for GHQ, PTSD, and symptoms were considered to have psychological symptoms.

Results

12.4% of the participants were medically downgraded. The majority (70.4%) had social or work limitations. Medically downgraded personnel had higher odds ratios in comparison to non‐downgraded personnel for psychological distress 1.84 (95% CI 1.43 to 2.37), PTSD 3.06 (95% CI 1.82 to 5.15), and number of symptoms 2.37 (95% CI 2.37 1.62 to 3.47). GHQ, PTSD, and symptoms scores were mainly, but not exclusively, related to chronic physical injury.

Conclusions

Psychological symptoms are common among medically downgraded personnel. Although the mechanisms involved are unclear, tackling issues of psychological symptoms among these subjects could contribute to faster restitution to full employability in the Armed Forces.     

Brain tumours and exposure to pesticides: a case-control study in southwestern France

Background

Brain tumours are often disabling and rapidly lethal; their aetiology is largely unknown. Among potential risk factors, pesticides are suspected.

Objective

To examine the relationship between exposure to pesticides and brain tumours in adults in a population‐based case–control study in southwestern France.

Methods

Between May 1999 and April 2001, 221 incident cases of brain tumours and 442 individually matched controls selected from the general population were enrolled. Histories of occupational and environmental exposures, medical and lifestyle information were collected. A cumulative index of occupational exposure to pesticides was created, based on expert review of lifelong jobs and tasks. Separate analyses were performed for gliomas and meningiomas.

Results

A non‐statistically significant increase in risk was found for brain tumours when all types of occupational exposure to pesticides were considered (OR = 1.29, 95% CI 0.87 to 1.91) and slightly higher but still non‐statistically significant when gliomas were considered separately (OR = 1.47, 95% CI 0.81 to 2.66). In the highest quartile of the cumulative index, a significant association was found for brain tumours (OR = 2.16, 95% CI 1.10 to 4.23) and for gliomas (OR = 3.21, 95% CI 1.13 to 9.11), but not for meningiomas. A significant increase in risk was also seen for the treatment of home plants (OR = 2.24, 95% CI 1.16 to 4.30) owing to environmental exposure to pesticides.

Conclusions

These data suggest that a high level of occupational exposure to pesticides might be associated with an excess risk of brain tumours, and especially of gliomas.     

Delta-aminolevulinic acid dehydratase polymorphism and the relation between low level lead exposure and the Mini-Mental Status Examination in older men: the Normative Aging Study

Objective

To determine whether a polymorphism the in δ‐aminolevulinic acid dehydratase (ALAD) gene modifies the neurotoxicity of lead in older adults.

Methods

The authors studied men participating in the Department of Veterans Affairs'' Normative Aging Study, assessing their recent exposure to lead by measuring blood lead (n = 915) at each triennial clinic visit, and, beginning in 1991, assessing their cumulative exposure by measuring lead levels in tibia (n = 722) and patella (n = 720), using K‐shell x ray fluorescence. Starting in 1993 and again at each triennial visit, the authors administered the Mini‐Mental State Examination (MMSE) to assess their cognitive functioning. The relation of the lead biomarkers to MMSE score was evaluated and this association was compared among men who carried the variant allele, ALAD‐2, versus men without the allele.

Results

Sixteen per cent of men carried the ALAD‐2 allele. Median tibia and patella lead levels (first‐third quartile) were 19 (13–28) and 27 (18–39) μg/g. Blood lead levels were consistent with non‐occupational exposure: only 6% of men had levels ⩾10 μg/dl. In multivariable adjusted analyses, higher levels of blood lead were associated with poorer performance on the MMSE. This association was most pronounced among ALAD‐2 carriers, among whom a 3 μg/dl increment in blood lead (the interquartile range) was associated with a 0.26 point lower mean MMSE score (95% CI −0.54 to 0.01), compared with a 0.04 point lower score (95% CI −0.16 to 0.07) among non‐carriers. The modest 0.22 point difference in these associations did not attain statistical significance, however (p_interaction = 0.13). The associations between bone lead levels and MMSE score did not vary by ALAD‐2 status.

Conclusions

Although not statistically significant, these findings suggest that ALAD genotype may modify blood lead''s adverse association with cognition among older men who had community exposures to lead. However, despite a relatively large sample size and the use of sensitive methods for measuring lead burden, the evidence overall was fairly weak.     

Health-related job loss: findings from a community-based survey

Aims

To explore the frequency, nature, determinants and outcome of health‐related job loss (HRJL) in men sampled from the general population of three rural areas.

Methods

Data on lifetime occupational history, including any HRJL, were obtained as part of a postal survey of men aged 24–70 years in three rural areas of England and Wales. Incidence rates were calculated for first health‐related loss of a job that had been held for ⩾1 year. Associations with risk factors were examined by Poisson regression, and by application of conditional logistic regression in a nested case–control study.

Results

HRJL was reported by 1408 (13%) of the 10 559 men who had held long‐term jobs. The incidence rose steeply with age for cardiorespiratory and neurological disorders, but for accidents and poisoning the trend was, if anything, in the reverse direction. An increase in incidence over time was most marked for musculoskeletal disorders and mental illness, and much less prominent for cardiorespiratory and neurological disease. In comparison with other occupations, the risk was lower in agricultural workers (odds ratio (OR) 0.6, 95% CI 0.5 to 0.8), and higher in policemen (OR 2.4, 95% CI 1.6 to 3.7) and teachers (OR 2.0, 95% CI 1.5 to 2.7), this differential being even greater for HRJL caused by mental illness. Risk was also increased in employees relative to the self‐employed (OR 2.0, 95% CI 1.7 to 2.3). Shift work was associated with a higher incidence of job loss caused by mental illness (OR 1.5, 95%CI 1.1–2.2), and heavy lifting with HRJL caused by musculoskeletal disorders (OR 2.6, 95% CI 2.0 to 3.5). After HRJL, 61% of subjects had subsequently obtained further long‐term employment, usually within 1 year.

Conclusions

In the population studied, HRJL has become increasingly common, especially in relation to musculoskeletal disorders and mental illness. In addition to being associated with ergonomic stresses in the workplace, it may be importantly influenced by cultural and economic factors. Future research should focus on the minority of workers who leave a job for health reasons and do not rapidly return to further work.Like many other European countries, the UK currently faces an economic challenge in providing for a growing elderly population at a time when young people are entering the workforce later and many older workers are leaving employment before the normal retirement age.¹ Thus, in its recently launched 5‐year strategy for social security, the British government identified a national employment rate of 80% as its aspiration.² Achieving this goal will require the minimisation of unemployment not only among those traditionally deemed eligible to work but also among people with disabilities who previously have been regarded as outside the labour market. To avoid wasting valuable skills and experience, there will be an imperative to reduce unnecessary health‐related job loss (HRJL) and to promote the redeployment of people who have left jobs for reasons of ill‐health.One particular concern has been the high rate of early retirement because of ill‐health among public‐sector employees,³ which is likely to be driven, at least partly, by relatively generous financial provisions in their pension schemes. There have been calls to apply stricter and more uniform criteria in determining eligibility for ill‐health retirement in these groups,^3,4 At the same time, however, there is a need for balance, and an approach that is too stringent could cause unjustified hardship.To investigate the frequency, nature, determinants and outcome of HRJL, we analysed data from a survey of men living in three rural areas of England and Wales. In particular, we explored differences between agricultural workers, many of whom were self‐employed or worked in small businesses, and two major groups of public sector employees: policemen and teachers.