Long-term use of cellular phones and brain tumours: increased risk associated with use for > or =10 years

Aim

To evaluate brain tumour risk among long‐term users of cellular telephones.

Methods

Two cohort studies and 16 case–control studies on this topic were identified. Data were scrutinised for use of mobile phone for ⩾10 years and ipsilateral exposure if presented.

Results

The cohort study was of limited value due to methodological shortcomings in the study. Of the 16 case–control studies, 11 gave results for ⩾10 years'' use or latency period. Most of these results were based on low numbers. An association with acoustic neuroma was found in four studies in the group with at least 10 years'' use of a mobile phone. No risk was found in one study, but the tumour size was significantly larger among users. Six studies gave results for malignant brain tumours in that latency group. All gave increased odd ratios (OR), especially for ipsilateral exposure. In a meta‐analysis, ipsilateral cell phone use for acoustic neuroma was OR = 2.4 (95% CI 1.1 to 5.3) and OR = 2.0, (1.2 to 3.4) for glioma using a tumour latency period of ⩾10 years.

Conclusions

Results from present studies on use of mobile phones for ⩾10 years give a consistent pattern of increased risk for acoustic neuroma and glioma. The risk is highest for ipsilateral exposure.     

Mobile phone use and acoustic neuroma risk in Japan

Objectives

The rapid increase of mobile phone use has increased public concern about its possible health effects in Japan, where the mobile phone system is unique in the characteristics of its signal transmission. To examine the relation between mobile phone use and acoustic neuroma, a case‐control study was initiated.

Methods

The study followed the common, core protocol of the international collaborative study, INTERPHONE. A prospective case recruitment was done in Japan for 2000–04. One hundred and one acoustic neuroma cases, who were 30–69 years of age and resided in the Tokyo area, and 339 age, sex, and residency matched controls were interviewed using a common computer assisted personal interview system. Education and marital status adjusted odds ratio was calculated with a conditional logistic regression analysis.

Results

Fifty one cases (52.6%) and 192 controls (58.2%) were regular mobile phone users on the reference date, which was set as one year before the diagnosis, and no significant increase of acoustic neuroma risk was observed, with the odds ratio (OR) being 0.73 (95% CI 0.43 to 1.23). No exposure related increase in the risk of acoustic neuroma was observed when the cumulative length of use (<4 years, 4–8 years, >8 years) or cumulative call time (<300 hours, 300–900 hours, >900 hours) was used as an exposure index. The OR was 1.09 (95% CI 0.58 to 2.06) when the reference date was set as five years before the diagnosis. Further, laterality of mobile phone use was not associated with tumours.

Conclusions

These results suggest that there is no significant increase in the risk of acoustic neuroma in association with mobile phone use in Japan.     

Household exposure to pesticides and risk of childhood acute leukaemia

Objectives

To investigate the relation between childhood acute leukaemia and household exposure to pesticides.

Methods

The study included 280 incident cases of acute leukaemia and 288 controls frequency matched on gender, age, hospital, and ethnic origin. The data were obtained from standardised face to face interviews of the mothers with detailed questions on parental occupational history, home and garden insecticide use, and insecticidal treatment of pediculosis. Odds ratios were estimated using unconditional regression models including the stratification variables parental socioeconomic status and housing characteristics.

Results

Acute leukaemia was observed to be significantly associated with maternal home insecticide use during pregnancy (OR = 1.8, 95% CI 1.2 to 2.8) and during childhood (OR = 1.7, 95% CI 1.1 to 2.4), with garden insecticide use (OR = 2.4, 95% CI 1.3 to 4.3), and fungicide use (OR = 2.5, 95% CI 1.0 to 6.2) during childhood. Insecticidal shampoo treatment of pediculosis was also associated with childhood acute leukaemia (OR = 1.9, 95% CI 1.2 to 3.3).

Conclusion

The results reported herein support the hypothesis that various types of insecticide exposure may be a risk factor for childhood acute leukaemia. The observed association with insecticidal shampoo treatment of pediculosis, which has never been investigated before, requires further study.     

The effectiveness of graded activity for low back pain in occupational healthcare

Background

Low back pain is a common medical and social problem associated with disability and absence from work. Knowledge on effective return to work (RTW) interventions is scarce.

Objective

To determine the effectiveness of graded activity as part of a multistage RTW programme.

Design

Randomised controlled trial.

Setting

Occupational healthcare.

Subjects

112 workers absent from work for more than eight weeks due to low back pain were randomised to either graded activity (n = 55) or usual care (n = 57).

Intervention

Graded activity, a physical exercise programme aimed at RTW based on operant‐conditioning behavioural principles.

Main outcome measures

The number of days off work until first RTW for more then 28 days, total number of days on sick leave during follow up, functional status, and severity of pain. Follow up was 26 weeks.

Results

Graded activity prolonged RTW. Median time until RTW was equal to the total number of days on sick leave and was 139 (IQR = 69) days in the graded activity group and 111 (IQR = 76) days in the usual care group (hazard ratio = 0.52, 95% CI 0.32 to 0.86). An interaction between a prior workplace intervention and graded activity, together with a delay in the start of the graded activity intervention, explained most of the delay in RTW (hazard ratio = 0.86, 95% CI 0.40 to 1.84 without prior intervention and 0.39, 95% CI 0.19 to 0.81 with prior intervention). Graded activity did not improve pain or functional status clinically significantly.

Conclusions

Graded activity was not effective for any of the outcome measures. Different interventions combined can lead to a delay in RTW. Delay in referral to graded activity delays RTW. In implementing graded activity special attention should be paid to the structure and process of care.     

Occupational risk factors for nasopharyngeal cancer among female textile workers in Shanghai, China

Aims

To investigate whether occupational exposure to dusts and chemicals in the Chinese textile industry are associated with risk of nasopharyngeal cancer.

Methods

Sixty seven nasopharyngeal carcinoma (NPC) cases identified during 1989–98 and a random sample (n = 3188) of women were included in a case cohort study nested in a cohort of 267 400 women textile workers in Shanghai, China. A complete occupational history of work in the textile industry was obtained for each woman. A job exposure matrix developed by experienced industrial hygienists was used to assess exposures to specific dusts and chemicals.

Results

Risk of NPC is associated with cumulative exposure to cotton dust. The hazard ratio for women cumulatively exposed to >143.4 mg/m³ × years of cotton dust was 3.6 (95% CI 1.8 to 7.2) compared with unexposed women. Trends of increasing risk were also found with increasing duration of exposure to acids and caustics (p = 0.05), and with years worked in dyeing processes (p = 0.06). Women who worked at least 10 years in dyeing processes had a 3.6‐fold excess risk of NPC (95% CI 1.0 to 12.1).

Conclusions

Occupational exposure to cotton dust, acids, and caustics, and work in dyeing and printing jobs in the textile industry may have increased risk of NPC in this cohort.     

Healthcare use before and after a workplace injury in British Columbia, Canada

Objectives

There is growing evidence that occupational injuries influence workers'' emotional and physical wellbeing, extending healthcare use beyond what is covered by the Workers'' Compensation Board (WCB).

Methods

The authors used an administrative database that links individual publicly funded healthcare and WCB data for the population of British Columbia (BC), Canada. They examined change in service use, relative to one year before the injury, for workers who required time off for their injuries (lost time = LT) and compared them to other injured workers (no lost time = NLT) and individuals in the population who were not injured (non‐injured = NI).

Results

LT workers increased physician visits (22%), hospital days (50%), and mental healthcare use (43% physician visits; and 70% hospital days) five years after the injury, relative to the year before the injury, at a higher rate than the NI group. For the NLT workers, the level of increased use following the injury was between that of these two groups. These patterns persisted when adjusting for registration in the BC Medical Service Plan (MSP) and several workplace characteristics.

Conclusions

Although the WCB system is the primary mechanism for processing claims and providing information about workplace injury, it is clear that the consequences of workplace injury extend beyond what is covered by the WCB into the publicly funded healthcare system.     

Mortality from non-malignant diseases in a cohort of female pulp and paper workers in Norway

Objectives

The objective of the present study was to investigate the risk of death from non‐malignant diseases in female pulp and paper workers in Norway.

Methods

A total of 3143 women first employed between 1920–93 were included in the study cohort. Information about each cohort member was obtained from personnel record files in the mills in order to identify employment periods and job categories. Data on cause and date of death were added by linkage to the Cause of Death Register using unique personal identification numbers. The follow up period was 1951–2000. Standardised mortality ratios (SMRs) with 95% confidence intervals (95% CIs) were calculated using the national female mortality rates as reference. Poisson regression analysis was used to examine internal relations between the duration of employment in paper departments and the risk of death from selected causes. Relative risks (RRs) and 95% CIs were calculated.

Results

The study showed a significantly increased risk for total non‐malignant mortality (SMR = 1.14, 95% CI 1.05 to 1.24), mainly due to increased mortality from ischaemic heart disease (SMR = 1.22, 95% CI 1.03 to 1.43) and cerebrovascular diseases (SMR = 1.16, 95% CI 0.94 to 1.42). Analysis by department showed the highest risk of death in paper department workers with short term employment. Internal analyses showed a 5% and 9% increase in risk of dying from ischaemic heart disease and respiratory diseases, respectively, among paper department workers exposed to paper dust. The risk decreased with increasing duration of employment.

Conclusion

The increased risk of ischaemic heart diseases and respiratory diseases seen among employees of paper departments may be related to exposure to paper dust.     

Predictors of leaving nursing care: a longitudinal study among Swedish nursing personnel

Objectives

Despite extensive research on turnover among nursing personnel very little is known about the impact of physical workload and health on leaving. The aim of this study was to find predictors for leaving nursing care with special reference to physical working conditions and musculoskeletal problems.

Methods

This study is based on longitudinal data from a survey of nursing personnel who were employed at various county hospitals in Sweden from 1992–95. A self administrated follow up questionnaire was used to identify their present position in the labour market. The response rate was 73% (n = 1095).

Results

The results showed that nursing personnel reporting musculoskeletal problems of the neck/shoulder or knees and those who had limited use of transfer devices were more likely to leave nursing care.

Conclusions

The study highlights the importance of taking musculoskeletal problems and use of transfer devices into consideration in order to retain nursing personnel.     

Environmental risk factors for Parkinson's disease and parkinsonism: the Geoparkinson study

Objective

To investigate the associations between Parkinson''s disease and other degenerative parkinsonian syndromes and environmental factors in five European countries.

Methods

A case–control study of 959 prevalent cases of parkinsonism (767 with Parkinson''s disease) and 1989 controls in Scotland, Italy, Sweden, Romania and Malta was carried out. Cases were defined using the United Kingdom Parkinson''s Disease Society Brain Bank criteria, and those with drug‐induced or vascular parkinsonism or dementia were excluded. Subjects completed an interviewer‐administered questionnaire about lifetime occupational and hobby exposure to solvents, pesticides, iron, copper and manganese. Lifetime and average annual exposures were estimated blind to disease status using a job‐exposure matrix modified by subjective exposure modelling. Results were analysed using multiple logistic regression, adjusting for age, sex, country, tobacco use, ever knocked unconscious and family history of Parkinson''s disease.

Results

Adjusted logistic regression analyses showed significantly increased odds ratios for Parkinson''s disease/parkinsonism with an exposure–response relationship for pesticides (low vs no exposure, odds ratio (OR) = 1.13, 95% CI 0.82 to 1.57, high vs no exposure, OR = 1.41, 95% CI 1.06 to 1.88) and ever knocked unconscious (once vs never, OR = 1.35, 95% CI 1.09 to 1.68, more than once vs never, OR = 2.53, 95% CI 1.78 to 3.59). Hypnotic, anxiolytic or antidepressant drug use for more than 1 year and a family history of Parkinson''s disease showed significantly increased odds ratios. Tobacco use was protective (OR = 0.50, 95% CI 0.42 to 0.60). Analyses confined to subjects with Parkinson''s disease gave similar results.

Conclusions

The association of pesticide exposure with Parkinson''s disease suggests a causative role. Repeated traumatic loss of consciousness is associated with increased risk.     

Mortality among Paris sewage workers

Objectives

To describe the mortality of Paris sewage workers.

Methods

A cohort of all Paris sewage workers since 1970 was established and followed up in mortality until 1999. The causes of death were determined by matching with a national database. The mortality rates were compared to the rates of a local reference population.

Results

A large excess in mortality (standardised mortality ratio (SMR) = 1.25; 530 cases, 95% CI 1.15 to 1.36) and in particular mortality from cancer (SMR = 1.37, 235 cases) was detected which was particularly important in the subgroup of subjects who had left employment because they resigned or were laid off (SMR = 1.77; 50 cases). The excess mortality is to a large extent due to alcohol related diseases (SMR = 1.65, 122 cases) especially malignant (SMR = 1.85, 16 cases) and non‐malignant (SMR =  1.68, 38 cases) liver diseases, lung cancer (SMR = 1.47, 68 cases), and infectious diseases (SMR =  1.86, 25 cases). The SMRs for some diseases (all cancers, cancers of the oesophagus and lung, all alcohol related diseases) seem to increase with duration of employment as a sewage worker. Other than lung cancer, smoking related diseases were not in excess.

Conclusion

The increased mortality by both malignant and non‐malignant liver diseases is probably due to excessive alcohol consumption, but could be partially the result of occupational exposure to chemical and infectious agents and interactions of these factors. The excess lung cancer is unlikely to be due to an increased smoking prevalence.     

Long term health complaints following the Amsterdam Air Disaster in police officers and fire-fighters

Background

On 4 October 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, the Netherlands. Fire‐fighters and police officers assisted with the rescue work.

Objectives

To examine the long term health complaints in rescue workers exposed to a disaster.

Methods

A historical cohort study was performed among police officers (n = 834) and fire‐fighters (n = 334) who performed at least one disaster related task and reference groups of their non‐exposed colleagues (n = 634 and n = 194, respectively). The main outcome measures included digestive, cardiovascular, musculoskeletal, nervous system, airway, skin, post‐traumatic stress, fatigue, and general mental health complaints; haematological and biochemical laboratory values; and urinalysis outcomes.

Results

Police officers and fire‐fighters who were professionally exposed to a disaster reported more physical and mental health complaints, compared to the reference groups. No clinically relevant statistically significant differences in laboratory outcomes were found.

Conclusions

This study is the first to examine long term health complaints in a large sample of rescue workers exposed to a disaster in comparison to reference groups of non‐exposed colleagues. Findings show that even in the long term, and in the absence of laboratory abnormalities, rescue workers report more health complaints.     

A Study on the Role of Mobile Phone Communication in Tuberculosis DOTS Treatment

Background:

Every year, a lot of Tuberculosis (TB) patients undergo Directly Observed Treatment Short-course (DOTS) in Salem city, one of the high TB districts in South India. Mobile phone usage among these patients and health workers is common. Mobile phone communication has a great potential in TB treatment.

Objectives:

To analyze the mobile phone usage and its effectiveness in TB DOTS treatment.

Materials and Methods:

A cross-sectional survey with 150 TB patients was followed by a focus group discussion with treatment supervisors, DOTS providers, and health workers.

Results:

Majority of patients use mobile phones to make calls to health workers to clarify their doubts on side effects, food, and symptoms of the disease. TB treatment supervisors effectively use mobile phones to counsel patients to adhere to the treatment regimen. Patients see mobile phones as a useful communication tool in TB treatment though they prefer direct interpersonal communication with health workers. Though the mobile ownership is 68% among the TB patients, many of them are not able to send text messages or read messages in English.

Conclusion:

Mobile phone possession and usage is high among the patients. Patients need to be trained to use mobile phone features such as alarm, voice mail, and interactive voice response. Incentives like free talk time and short message service (SMS) will encourage patients to communicate frequently with health workers, thereby, increasing the chances of better adherence to DOTS. SMS could be made available in the regional languages.     

Latex allergy: a follow up study of 1040 healthcare workers

Background

Natural rubber latex allergy can cause skin and respiratory symptoms The aim of this study was to evaluate the prevalence and incidence of latex related symptoms and sensitisation among a large group of healthcare workers in Trieste hospitals, followed for three years before and after the introduction of powder‐free gloves with low latex release.

Methods

In the years 1997–99 the authors evaluated 1040 healthcare workers exposed to latex allergen for latex related symptoms and sensitisation by means of a questionnaire, a medical examination, skin prick tests, and IgE specific antibody assay. The second evaluation was carried out in the years 2000–02, subsequent to the changeover to a powder‐free environment.

Results

Glove related symptoms were seen in 21.8% of the nurses (227), mostly consisting of mild dermatitis: 38 (3.6%) complaining of contact urticaria and 24 (2.3%) of asthma and/or rhinitis. These symptoms were significantly related to skin prick tests positive to latex (OR = 9.70; 95% CI 5.5 to 17) and to personal atopy (OR = 2.29; 95% CI 1.6 to 3.2). Follow up was completed in 960 subjects (92.3%): 19 new subjects (2.4%) complained of itching erythema when using gloves, but none was prick positive to latex. Symptoms significantly improved and in most cases disappeared (p<0.0001).

Conclusions

Simple measures such as the avoidance of unnecessary glove use, the use of non‐powdered latex gloves by all workers, and use of non‐latex gloves by sensitised subjects can stop the progression of latex symptoms and can avoid new cases of sensitisation.     

Use of mobile phones in an emergency reporting system for infectious disease surveillance after the Sichuan earthquake in China

Problem

Quick detection and response were essential for preventing outbreaks of infectious diseases after the Sichuan earthquake. However, the existing public health communication system in Sichuan province, China, was severely damaged by the earthquake.

Approach

The Chinese Center for Disease Control and Prevention set up a mobile phone emergency reporting system. In total, 495 light-powered mobile phones were delivered to local health-care agencies in earthquake affected areas. All phones were loaded with software designed for inputting and transmitting cases of infectious disease directly to a national database for further analysis.

Local setting

The emergency reporting system was set up in 14 counties hit hardest by the earthquake in Sichuan province, China.

Relevant changes

One week after delivering mobile phones to earthquake-affected areas, the number of health-care agencies at the township level that had filed reports returned to the normal level. The number of cases reported by using mobile phones accounted for as much as 52.9% of the total cases reported weekly from 19 May to 13 July in those areas

Lessons learned

The mobile phone is a useful communication tool for infectious disease surveillance in areas hit by natural disasters. Nevertheless, plans must be made ahead of time and be included in emergency preparedness programmes.     

Chronic bronchitis and urban air pollution in an international study

Objectives

The chronic effects of urban air pollution are not well known. The authors'' aim was to investigate the association between the prevalence and new onset of chronic bronchitis and urban air pollution.

Methods

Subjects from the general population randomly selected for the European Community Respiratory Health Survey (ECRHS I) during 1991–93 in 21 centres in 10 countries were followed up from the years 2000 to 2002 (n = 3232 males and 3592 females; average response rate = 65.3%). PM_2.5 and elements, with the same equipment at centre level, and home outdoor NO₂ in 1634 individuals were measured. Hierarchical models were used.

Results

The prevalence and new onset of chronic phlegm during follow up were 6.9% and 4.5%, respectively, 5.3% in males and 3.5% in females. Smoking, rhinitis, poor education, and low social class were associated with (prevalence and new onset of) chronic phlegm in both genders, and occupational exposures in males and traffic intensity (adjusted odds ratio for constant traffic, OR = 1.86; 95% CI 1.24 to 2.77) as well as home outdoor NO₂ (OR > 50 μg/m³v < 20μg³  =  2.71; 95% CI 1.03 to 7.16) among females. PM_2.5 and S content at centre level did not show any association with prevalence or new onset of chronic phlegm. Similar results were obtained with chronic productive cough.

Conclusion

Individual markers of traffic at household level such as reported intensity and outdoor NO₂ were risk factors for chronic bronchitis among females.     

A higher risk of congenital anomalies in the offspring of personnel who served aboard a Norwegian missile torpedo boat

Background

In the 1990s, congenital anomalies were reported among children whose fathers had served aboard a Norwegian missile torpedo boat (MTB). The Royal Norwegian Navy asked the University of Bergen to look into this problem as one part of a general health and work environment surveillance.

Aims

To estimate any increased risk of having children with congenital anomalies and having stillborn children among the offspring of workers that had served aboard the MTB and to investigate possible differences in exposure and other risk factors between these groups.

Methods

Data from a cross‐sectional study among all current employees of the Norwegian Navy (n = 2265, response rate 58%) were analysed.

Results

The prevalence ratio of having a child with congenital malformations associated with working on the ship was 4.0 (95% CI 1.9 to 8.6). The prevalence ratio of having a child who was stillborn or died within one week was 4.1 (95% CI 1.7 to 9.9).

Conclusion

Service aboard the MTB was associated with an increased risk of having children with congenital birth defects and having children that were stillborn. The causes of these findings are unknown.     

Global magnitude of reported and unreported mesothelioma

Background

Little is known about the global magnitude of mesothelioma. In particular, many developing countries, including some with extensive historical use of asbestos, do not report mesothelioma.

Objectives

We estimated the global magnitude of mesothelioma accounting for reported and unreported cases.

Methods

For all countries with available data on mesothelioma frequency and asbestos use (n = 56), we calculated the 15-year cumulative number of mesotheliomas during 1994–2008 from data available for fewer years and assessed its relationship with levels of cumulative asbestos use during 1920–1970. We used this relationship to predict the number of unreported mesotheliomas in countries for which no information on mesothelioma is available but which have recorded asbestos use (n = 33).

Results

Within the group of 56 countries with data on mesothelioma occurrence and asbestos use, the 15-year cumulative number of mesothelioma was approximately 174,300. There was a statistically significant positive linear relation between the log-transformed national cumulative mesothelioma numbers and the log-transformed cumulative asbestos use (adjusted R² = 0.83, p < 0.0001). Extrapolated to the group of 33 countries without reported mesothelioma, a total of approximately 38,900 (95% confidence interval, 36,700–41,100) mesothelioma cases were estimated to have occurred in the 15-year period (1994–2008).

Conclusions

We estimate conservatively that, globally, one mesothelioma case has been overlooked for every four to five reported cases. Because our estimation is based on asbestos use until 1970, the many countries that increased asbestos use since then should anticipate a higher disease burden in the immediate decades ahead.     

Effort/reward imbalance and sedentary lifestyle: an observational study in a large occupational cohort

Objectives

To investigate the association between effort/reward imbalance (ERI) at work and sedentary lifestyle.

Methods

Cross sectional data from the ongoing Finnish Public Sector Study related to 30 433 women and 7718 men aged 17–64 were used (n = 35 918 after exclusion of participants with missing values in covariates). From the responses to a questionnaire, an aggregated mean score for ERI in a work unit was assigned to each participant. The outcome was sedentary lifestyle defined as <2.00 metabolic equivalent task (MET) hours/day. Logistic regression with generalised estimating equations was used as an analysis method to include both individual and work unit level predictors in the models. Adjustments were made for age, marital status, occupational status, job contract, smoking, and heavy drinking.

Results

Twenty five per cent of women and 27% of men had a sedentary lifestyle. High individual level ERI was associated with a higher likelihood of sedentary lifestyle both among women (odds ratio (OR) = 1.08, 95% CI 1.01 to 1.16) and men (OR = 1.17, 95% CI 1.02 to 1.33). These associations were not explained by relevant confounders and they were also independent of work unit level job strain measured as a ratio of job demands and control.

Conclusions

A mismatch between high occupational effort spent and low reward received in turn seems to be associated with an increased risk of sedentary lifestyle, although this association is relatively weak.     

Predicting the long term course of low back pain and its consequences for sickness absence and associated work disability

Background

Low back pain is characterised by a dynamic pattern of episodes and recovery but little is known about the long term course of back pain due to lack of cohort studies with sufficiently long follow up periods.

Methods

A cohort of 523 workers in nursing homes and homes for the elderly was followed for two years. Physical load was measured by observations at the workplace. Psychosocial factors at work, individual characteristics, and low back pain were determined by questionnaire once a year. The effect of work load on low back pain and the transition of low back pain into sickness absence was calculated with logistic regression analysis. A Markov model was used to construct a hypothetical cohort of workers with follow up of 40 years (40 cycles of 1 year) with transitional probabilities between no complaints, low back pain, and sickness due to low back pain. Permanent disability was used as end state of health.

Results

The transitional probability from no complaints to low back pain varied between p = 0.25 and p = 0.29, from low back pain to sickness absence between p = 0.09 and p = 0.25, and recurrence of sickness absence varied between p = 0.27 and p = 0.50, depending on the level of physical load. During a 40 year career, total sickness absence due to low back pain was approximately 140 weeks (6.6%) among workers with high physical load and about 30 weeks (1.4%) among those with low physical load.

Conclusion

The Markov approach illustrated the potential impact of physical load on (permanent) disability due to low back pain among workers with exposure to physical load. These consequences may go unnoticed in cohort studies with follow up periods of a few years.