Human exposure to molds, mycotoxins, and water-damaged buildings can cause neurologic and neuropsychiatric signs and symptoms. Many of these clinical features can partly mimic or be similar to classic neurologic disorders including pain syndromes, movement disorders, delirium, dementia, and disorders of balance and coordination. In this article, the author delineates the signs and symptoms of a syndrome precipitated by mold and mycotoxin exposure and contrasts and separates these findings neurodiagnostically from known neurologic diseases. This clinical process is designed to further the scientific exploration of the underlying neuropathophysiologic processes and to promote better understanding of effects of mold/mycotoxin/water-damaged buildings on the human nervous system and diseases of the nervous system. It is clear that mycotoxins can affect sensitive individuals, and possibly accelerate underlying neurologic/pathologic processes, but it is crucial to separate known neurologic and neuropsychiatric disorders from mycotoxin effects in order to study it properly.
"Friday, October 23, 2009
Neurologic and neuropsychiatric syndrome features of mold and mycotoxin exposure
Sunday, October 18, 2009
Hydroxypyrene in urine of football players after playing on artificial sports field with tire crumb infill
An analysis of MRI and ultrasound imaging in patients with gout who have normal plain radiographs
Objective. The aim of this study was to analyse the prevalence of occult destructive arthropathy in subjects with gout and normal plain radiographs by utilizing MRI and ultrasound (US).
Methods. The study consisted of two visits. At Visit 1, a plain radiograph of the ‘index joint’ was obtained. The ‘index joint’ was defined as a joint that has had the most acute attacks of gout historically. The index joint plain radiograph had to be free of erosive damage in order for the subject to qualify for Visit 2. At Visit 2, the subject had an MRI with contrast and an US of the index joint. Each subject also had an MRI and US of an ‘asymptomatic joint’. The ‘asymptomatic joint’ was defined as a joint that had never experienced an acute attack of gout (determined by standard protocol). The primary endpoint was erosive changes on the MRI and/or US of the index joint. Secondary endpoints included erosive changes on the asymptomatic joint as well as bone marrow oedema (BME) (on MRI), synovial pannus (SP), soft tissue tophi (STT) or oedema (STE) on either the index or asymptomatic joint.
Results. Twenty-seven subjects (26 males; 1 female) completed both visits. Their average age and disease duration were 55.1 years (range 21–75 years) and 6.8 years (range 0.25–25 years), respectively. The subjects’ average serum uric acid level over the past 5 years was 8.09 mg/dl (range 4.1–12.8 mg/dl); their average on the day of Visit 1 was 7.96 mg/dl (range 4.6–13.9 mg/dl). The first MTP was the most common index joint (17) followed by the ankle (5), mid-tarsal (2), knee (2) and wrist (1). The knee was the most common asymptomatic joint (21) followed by the wrist (3), MTP (2) and ankle (1). All subjects had both MRIs; one subject refused the US. Out of 27 subjects, 15 (56%) had erosions on MRI of their index joint (P < 0.0001); only 1 subject (4%) had erosions identified in the index joint by US (P = NS). Regarding the secondary endpoints on the index joint, the MRI detected SP (13), BME (4), STE (3) and STT (0); the US detected SP (1), STT (1) and STE (0). Regarding the MRI of the asymptomatic joint, positive findings included SP (3), BME (3), STE (2) and erosions (1). There were no positive findings by US in the asymptomatic joint.
Conclusions. A large percentage of patients with gout and normal plain radiographs have occult destructive arthropathy that is only detected by advanced imaging such as MRI and/or US. However, MRI appears to be much more sensitive than US at detecting these findings."
Hand deformities are important signs of disease severity in patients with early rheumatoid arthritis
Objectives. The aim of this study was to investigate the occurrence and significance of hand deformities during the first 10 years of RA.
Methods. One hundred and eighty-three early RA patients were included in the study during 1985–89. Mean ± s.d. of age at onset was 51.4 ± 12.4 years, and mean duration of symptoms before inclusion 12 ± 7 months; 64% were women. The patients were followed annually. Assessment of hand deformities was standardized. Hand mobility was measured by signals of functional impairment (SOFI), disability by HAQ and hand HAQ, disease activity by ESR and radiographic changes by the Larsen method.
Results. One hundred and eight (59%) patients developed at least one hand deformity during the study time. The majority occurred during the first years. After 10 years, the rate of ulnar deviation, button hole deformity and swan neck deformity was 44, 24 and 23.5%, respectively. The deformity group showed significantly higher disease activity during the first 5 years, and significantly more hand impairment, more disability and more severe radiographic changes throughout the study. Presence of a deformity after 1 year increased the risk of developing a Larsen score above median after 5 years. Odds ratio (95% CI) was 2.1 (1.023, 4.385).
Conclusions. More than half of the patients in this early RA cohort had developed hand deformities after 10 years. Most deformities occurred during the first year of the disease. Presence of hand deformities had an impact on daily life function and added useful prognostic information, being an early sign of a more severe disease."
Ultrasound lung comets in systemic sclerosis: a chest sonography hallmark of pulmonary interstitial fibrosis
Objective. To assess the correlation between ultrasound lung comets (ULCs, a recently described echographic sign of interstitial lung fibrosis) and the current undisputed gold-standard high-resolution CT (HRCT) to detect pulmonary fibrosis in patients with SSc.
Methods. We enrolled 33 consecutive SSc patients (mean age 54 ± 13 years, 30 females) in the Rheumatology Clinic of the University of Pisa. We assessed ULCs and chest HRCT within 1 week independently in all the patients. ULC score was obtained by summing the number of lung comets on the anterior and posterior chest. Pulmonary fibrosis was quantified by HRCT with a previously described 30-point Warrick score.
Results. Presence of ULCs (defined as a total number more than 10) was observed in 17 (51%) SSc patients. Mean ULC score was 37 ± 50, higher in the diffuse than in the limited form (73 ± 66 vs 21 ± 35; P < 0.05). A significant positive linear correlation was found between ULCs and Warrick scores (r = 0.72; P < 0.001).
Conclusions. ULCs are often found in SSc, are more frequent in the diffuse than the limited form and are reasonably well correlated with HRCT-derived assessment of lung fibrosis. They represent a simple, bedside, radiation-free hallmark of pulmonary fibrosis of potential diagnostic and prognostic value.
"Vital Signs: Awareness: Prodding People to Wash Their Hands in Restrooms
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Saturday, October 17, 2009
Really?: The Claim: Always Wash Your Hands With Hot Water, Not Cold
Soap and warm water have long been said to prevent the spread of infections, but is warm or hot water really more effective than cold?
In its medical literature, the Food and Drug Administrationstates that hot water comfortable enough for washing hands is not hot enough to kill bacteria, but is more effective than cold water because it removes oils from the hand that can harbor bacteria.
But in a 2005 report in the Journal of Occupational and Environmental Medicine, scientists with the Joint Bank Group/Fund Health Services Department pointed out that in studies in which subjects had their hands contaminated, and then were instructed to wash and rinse with soap for 25 seconds using water with temperatures ranging from 40 degrees Fahrenheit to 120 degrees, the various temperatures had “no effect on transient or resident bacterial reduction.”
They found no evidence that hot water had any benefit, and noted that it might increase the “irritant capacity” of some soaps, causing contact dermatitis. “Temperature of water used for hand washing should not be guided by antibacterial effects but comfort,” they wrote, “which is in the tepid to warm temperature range. The usage of tepid water instead of hot water also has economic benefits.”
THE BOTTOM LINE
Hot water for hand washing has not been proved to remove germs better than cold water.
"Total retirement 'bad for you'
Friday, October 16, 2009
WA prisons ramp up Taser use - WA today
WA prisons ramp up Taser use WA today He said that since the devices were introduced, inmate injuries and Workcover claims by guards had dropped off markedly. "(The department has) absolutely ... |
Shame 'boosts hand-washing rate'
Tuesday, October 13, 2009
Developments in asbestos cancer risk assessment
Monday, October 12, 2009
Organizational justice and markers of inflammation: The Whitehall II study [Original article]
Objectives: Low organizational justice has been shown to be associated with increased risk of various health problems, but the underlying mechanisms remain unclear. We tested whether organisational injustice contributes to chronic inflammation in a population of middle-aged men and women.
Methods: This prospective cohort study uses data from 3205 men and 1204 women aged 35–55 years at entry into the Whitehall II study (Phase 1, 1985-1988). Organisational justice perceptions were assessed at Phase 1 and Phase 2 (1989-1990) and circulating inflammatory markers C-reactive protein and interleukin-6 at Phase 3 (1991-1993) and Phase 7 (2003-2004).
Results: In men, low organisational justice was associated with increased C-reactive protein levels at both follow-ups (Phase 3 and 7) and increased interleukin-6 at the second follow-up (Phase 7). The long term (Phase 7) associations were largely independent of covariates, such as age, employment grade, body mass index and depressive symptoms. In women, no relationship was found between organisational justice and C-reactive protein or interleukin-6.
Conclusions: This study suggests that organisational injustice is associated with increased long-term levels of inflammatory markers among men.
Justice at Work and Metabolic Syndrome: the Whitehall II Study [Original article]
Growing evidence shows that high levels of justice are beneficial for employee health, although biological mechanisms underlying this association are yet to be clarified. We aim to test whether high justice at work protects against metabolic syndrome.
Methods:A prospective cohort study of 20 civil service departments in London (the Whitehall II study) including 6123 male and female British civil servants aged 35 to 55 years without prevalent CHD at baseline (1985-1990). Perceived justice at work was determined by means of questionnaire on two occasions between 1985 and 1990. Follow-up for metabolic syndrome and its components occurring from 1990 through 2004 was based on clinical assessments on three occasions over more than 18 years.
Results:Cox proportional hazard models adjusted for age, ethnicity and employment grade showed that men who experienced a high level of justice at work had a lower risk of incident metabolic syndrome than employees with a low level of justice (hazard ratio 0.75; 95% confidence interval: 0.63-0.89). There was little evidence of an association between organizational justice and metabolic syndrome or its components in women (hazard ratio 0.88; 95%CI: 0.67-1.17).
Conclusions:Our prospective findings provide evidence of an association between high levels of justice at work and the development of metabolic syndrome in men.
Do pre-employment influences explain the association between psychosocial factors at work and coronary heart disease? The Whitehall II study. [Origina
To examine whether the association between psychosocial factors at work and incident coronary heart disease (CHD) is explained by pre-employment factors, such as family history of CHD, education, paternal education and social class, number of siblings, and height.
Methods:A prospective cohort study of 6435 British men aged 35-55 years at phase 1 (1985-1988) and free from prevalent CHD at phase 2 (1989-1990). Psychosocial factors at work were assessed at phases 1 and 2 and mean scores across the two phases were used to determine long-term exposure. Selected pre-employment factors were assessed at phase 1. Follow-up for coronary death, first non-fatal myocardial infarction or definite angina between phase 2 and 1999 was based on clinical records (250 events, follow-up 8.7 years).
Results:The selected pre-employment factors were associated with risk for CHD: hazard ratios (CI 95%) were 1.33 (1.03-1.73) for family history of CHD, 1.18 (1.05-1.32) for each quartile decrease in height, and 1.16 (0.99-1.35) for each category increase in number of siblings. Psychosocial work factors also predicted CHD: 1.72 (1.08-2.74) for low job control and 1.72 (1.10-2.67) for low organisational justice. Adjustment for pre-employment factors changed these associations by 4.1% or less.
Conclusions:In this well-characterised occupational cohort of British men, the association between psychosocial factors at work and CHD was largely independent of family history of CHD, education, paternal educational attainment and social class, number of siblings, and height.
Effects of Alcohol and Sleep Restriction on Simulated Driving Performance in Untreated Patients With Obstructive Sleep Apnea
Background: Because of previous sleep disturbance and sleep hypoxia, patients with obstructive sleep apnea (OSA) might be more vulnerable to the effects of alcohol and sleep restriction than healthy persons.
Objective: To compare the effects of sleep restriction and alcohol on driving simulator performance in patients with OSA and age-matched control participants.
Design: Driving simulator assessments in 2 groups under 3 different conditions presented in random order.
Setting: Adelaide Institute for Sleep Health, Sleep Laboratory, Adelaide, Australia.
Participants: 38 untreated patients with OSA and 20 control participants.
Measurements: Steering deviation, crashes, and braking reaction time.
Intervention: Unrestricted sleep, sleep restricted to a maximum of 4 hours, and ingestion of an amount of 40% vodka calculated to achieve a blood alcohol level of 0.05 g/dL.
Results: Patients with OSA demonstrated increased steering deviation compared with control participants (mean, 50.5 cm [95% CI, 46.1 to 54.9 cm] in the OSA group and 38.4 cm [CI, 32.4 to 44.4 cm] in the control group; P < 0.01) and significantly greater steering deterioration over time (group by time interaction, P = 0.02). The increase in steering deviation after sleep restriction and alcohol was approximately 40% greater in patients with OSA than in control participants (group by condition interaction, P = 0.04). Patients with OSA crashed more frequently than control participants (1 vs. 24 participants; odds ratio [OR], 25.4; P = 0.03) and crashed more frequently after sleep restriction (OR, 4.0; P < 0.01) and alcohol consumption (OR, 2.3; P = 0.02) than after normal sleep. In patients with OSA, prolonged eye closure (>2 seconds) and microsleeps (> 2 seconds of theta activity on electroencephalography) were significant crash predictors (OR, 19.2 and 7.2, respectively; P < 0.01). Braking reaction time was slower after sleep restriction than after normal sleep (mean, 1.39 [SD, 0.06] seconds vs. 1.22 [SD, 0.04] seconds; P < 0.01) but not after alcohol consumption. No group differences were found.
Limitation: Simulated driving was assessed rather than on-road driving.
Conclusion: Patients with OSA are more vulnerable than healthy persons to the effects of alcohol consumption and sleep restriction on various driving performance variables.
Primary Funding Source: Australian National Health and Medical Research Council.
Facemasks and Hand Hygiene to Prevent Influenza Transmission in Households: A Cluster Randomized Trial
Background: Few data are available about the effectiveness of nonpharmaceutical interventions for preventing influenza virus transmission.
Objective: To investigate whether hand hygiene and use of facemasks prevents household transmission of influenza.
Design: Cluster randomized, controlled trial. Randomization was computer generated; allocation was concealed from treating physicians and clinics and implemented by study nurses at the time of the initial household visit. Participants and personnel administering the interventions were not blinded to group assignment. (ClinicalTrials.gov registration number: NCT00425893)
Setting: Households in Hong Kong.
Patients: 407 people presenting to outpatient clinics with influenza-like illness who were positive for influenza A or B virus by rapid testing (index patients) and 794 household members (contacts) in 259 households.
Intervention: Lifestyle education (control) (134 households), hand hygiene (136 households), or surgical facemasks plus hand hygiene (137 households) for all household members.
Measurements: Influenza virus infection in contacts, as confirmed by reverse-transcription polymerase chain reaction (RT-PCR) or diagnosed clinically after 7 days.
Results: Sixty (8%) contacts in the 259 households had RT-PCR–confirmed influenza virus infection in the 7 days after intervention. Hand hygiene with or without facemasks seemed to reduce influenza transmission, but the differences compared with the control group were not significant. In 154 households in which interventions were implemented within 36 hours of symptom onset in the index patient, transmission of RT-PCR–confirmed infection seemed reduced, an effect attributable to fewer infections among participants using facemasks plus hand hygiene (adjusted odds ratio, 0.33 [95% CI, 0.13 to 0.87]). Adherence to interventions varied.
Limitation: The delay from index patient symptom onset to intervention and variable adherence may have mitigated intervention effectiveness.
Conclusion: Hand hygiene and facemasks seemed to prevent household transmission of influenza virus when implemented within 36 hours of index patient symptom onset. These findings suggest that nonpharmaceutical interventions are important for mitigation of pandemic and interpandemic influenza.
Primary Funding Source: Centers for Disease Control and Prevention.
ORIGINAL CONTRIBUTION: Association of an Educational Program in Mindful Communication With Burnout, Empathy, and Attitudes Among Primary Care Physicia
Context Primary care physicians report high levels of distress, which is linked to burnout, attrition, and poorer quality of care. Programs to reduce burnout before it results in impairment are rare; data on these programs are scarce.
Objective To determine whether an intensive educational program in mindfulness, communication, and self-awareness is associated with improvement in primary care physicians' well-being, psychological distress, burnout, and capacity for relating to patients.
Design, Setting, and Participants Before-and-after study of 70 primary care physicians in Rochester, New York, in a continuing medical education (CME) course in 2007-2008. The course included mindfulness meditation, self-awareness exercises, narratives about meaningful clinical experiences, appreciative interviews, didactic material, and discussion. An 8-week intensive phase (2.5 h/wk, 7-hour retreat) was followed by a 10-month maintenance phase (2.5 h/mo).
Main Outcome Measures Mindfulness (2 subscales), burnout (3 subscales), empathy (3 subscales), psychosocial orientation, personality (5 factors), and mood (6 subscales) measured at baseline and at 2, 12, and 15 months.
Results Over the course of the program and follow-up, participants demonstrated improvements in mindfulness (raw score, 45.2 to 54.1; raw score change [], 8.9; 95% confidence interval [CI], 7.0 to 10.8); burnout (emotional exhaustion, 26.8 to 20.0; = –6.8; 95% CI, –4.8 to –8.8; depersonalization, 8.4 to 5.9; = –2.5; 95% CI, –1.4 to –3.6; and personal accomplishment, 40.2 to 42.6; = 2.4; 95% CI, 1.2 to 3.6); empathy (116.6 to 121.2; = 4.6; 95% CI, 2.2 to 7.0); physician belief scale (76.7 to 72.6; = –4.1; 95% CI, –1.8 to –6.4); total mood disturbance (33.2 to 16.1; = –17.1; 95% CI, –11 to –23.2), and personality (conscientiousness, 6.5 to 6.8; = 0.3; 95% CI, 0.1 to 5 and emotional stability, 6.1 to 6.6; = 0.5; 95% CI, 0.3 to 0.7). Improvements in mindfulness were correlated with improvements in total mood disturbance (r = –0.39, P < .001), perspective taking subscale of physician empathy (r = 0.31, P < .001), burnout (emotional exhaustion and personal accomplishment subscales, r = –0.32 and 0.33, respectively; P < .001), and personality factors (conscientiousness and emotional stability, r = 0.29 and 0.25, respectively; P < .001).
Conclusions Participation in a mindful communication program was associated with short-term and sustained improvements in well-being and attitudes associated with patient-centered care. Because before-and-after designs limit inferences about intervention effects, these findings warrant randomized trials involving a variety of practicing physicians.
ORIGINAL CONTRIBUTION: Surgical Mask vs N95 Respirator for Preventing Influenza Among Health Care Workers: A Randomized Trial
Context Data about the effectiveness of the surgical mask compared with the N95 respirator for protecting health care workers against influenza are sparse. Given the likelihood that N95 respirators will be in short supply during a pandemic and not available in many countries, knowing the effectiveness of the surgical mask is of public health importance.
Objective To compare the surgical mask with the N95 respirator in protecting health care workers against influenza.
Design, Setting, and Participants Noninferiority randomized controlled trial of 446 nurses in emergency departments, medical units, and pediatric units in 8 tertiary care Ontario hospitals.
Intervention Assignment to either a fit-tested N95 respirator or a surgical mask when providing care to patients with febrile respiratory illness during the 2008-2009 influenza season.
Main Outcome Measures The primary outcome was laboratory-confirmed influenza measured by polymerase chain reaction or a 4-fold rise in hemagglutinin titers. Effectiveness of the surgical mask was assessed as noninferiority of the surgical mask compared with the N95 respirator. The criterion for noninferiority was met if the lower limit of the 95% confidence interval (CI) for the reduction in incidence (N95 respirator minus surgical group) was greater than –9%.
Results Between September 23, 2008, and December 8, 2008, 478 nurses were assessed for eligibility and 446 nurses were enrolled and randomly assigned the intervention; 225 were allocated to receive surgical masks and 221 to N95 respirators. Influenza infection occurred in 50 nurses (23.6%) in the surgical mask group and in 48 (22.9%) in the N95 respirator group (absolute risk difference, –0.73%; 95% CI, –8.8% to 7.3%; P = .86), the lower confidence limit being inside the noninferiority limit of –9%.
Conclusion Among nurses in Ontario tertiary care hospitals, use of a surgical mask compared with an N95 respirator resulted in noninferior rates of laboratory-confirmed influenza.
Trial Registration clinicaltrials.gov Identifier: NCT00756574
Published online October 1, 2009 (doi:10.1001/jama.2009.1466).
Cervical collar or physiotherapy versus wait and see policy for recent onset cervical radiculopathy: randomised trial [RESEARCH]
Objective To evaluate the effectiveness of treatment with collar or physiotherapy compared with a wait and see policy in recent onset cervical radiculopathy.
Design Randomised controlled trial.
Setting Neurology outpatient clinics in three Dutch hospitals.
Participants 205 patients with symptoms and signs of cervical radiculopathy of less than one month’s duration
Interventions Treatment with a semi-hard collar and taking rest for three to six weeks; 12 twice weekly sessions of physiotherapy and home exercises for six weeks; or continuation of daily activities as much as possible without specific treatment (control group).
Main outcome measures Time course of changes in pain scores for arm and neck pain on a 100 mm visual analogue scale and in the neck disability index during the first six weeks.
Results In the wait and see group, arm pain diminished by 3 mm/week on the visual analogue scale (β=–3.1 mm, 95% confidence interval –4.0 to –2.2 mm) and by 19 mm in total over six weeks. Patients who were treated with cervical collar or physiotherapy achieved additional pain reduction (collar: β=–1.9 mm, –3.3 to –0.5 mm; physiotherapy: β=–1.9, –3.3 to –0.8), resulting in an extra pain reduction compared with the control group of 12 mm after six weeks. In the wait and see group, neck pain did not decrease significantly in the first six weeks (β=–0.9 mm, –2.0 to 0.3). Treatment with the collar resulted in a weekly reduction on the visual analogue scale of 2.8 mm (–4.2 to –1.3), amounting to 17 mm in six weeks, whereas physiotherapy gave a weekly reduction of 2.4 mm (–3.9 to –0.8) resulting in a decrease of 14 mm after six weeks. Compared with a wait and see policy, the neck disability index showed a significant change with the use of the collar and rest (β=–0.9 mm, –1.6 to –0.1) and a non-significant effect with physiotherapy and home exercises.
Conclusion A semi-hard cervical collar and rest for three to six weeks or physiotherapy accompanied by home exercises for six weeks reduced neck and arm pain substantially compared with a wait and see policy in the early phase of cervical radiculopathy.
Trial registration Clinical trials NCT00129714.
[Articles] Surgery versus non-surgical therapy for carpal tunnel syndrome: a randomised parallel-group trial
[Articles] 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) poisoning in Victor Yushchenko: identification and measurement of TCDD metabolites
[Articles] Nortriptyline and gabapentin, alone and in combination for neuropathic pain: a double-blind, randomised controlled crossover trial
[Editorial] Is Europe fit for work?
Guidance Values for Surface Monitoring of Antineoplastic Drugs in German Pharmacies
Objectives: Antineoplastic drugs are widely used in anticancer therapy due to their cytotoxic activity but many of them are classified as carcinogenic, mutagenic, or teratogenic to humans. In order to evaluate personal exposure, surface monitoring has been successfully applied for several years. In this study, we present a statistical description of our data set from 102 German pharmacies and propose ‘threshold guidance values (TGVs)’ to facilitate interpretation of monitoring results.
Methods: Our database included 1008 results for platinum (PT) and 1237 for 5-fluorouracil (FU) collected in 102 pharmacies in Germany. Wipe sampling on site was performed with one validated procedure. PT concentrations were measured by voltammetry and FU by gas chromatography/mass spectrometry. Data were stratified into 10 locations and statistically evaluated.
Results: Contamination was detected on all surfaces in the pharmacies with high levels on storage shelves and floors. The median values for the different locations ranged from 0.20 to 1.70 pg cm–2 (mean: 0.57 pg cm–2) for PT and from 2.50 to 10.00 pg cm–2 (mean: 5.34 pg cm–2) for FU. The mean 75th percentiles were 3.92 pg cm–2 (PT) and 28.90 pg cm–2 (FU). The TGV 1 value was set at the median value and results below demonstrate good working practices. Contaminations above the TGV 2, which was assigned at the 75th percentile, show a clear need for optimizing the handling procedures.
Conclusions: The introduction of TGVs helps to reduce occupational exposure and allows pharmacy personnel to benchmark their own contamination levels. This provides a basis for improvement in occupational safety precautions and for regular contamination controls.
Trends in Wood Dust Inhalation Exposure in the UK, 1985-2005
Objectives: Wood dust data held in the Health and Safety Executive (HSE) National Exposure DataBase (NEDB) were reviewed to investigate the long-term changes in inhalation exposure from 1985 to 2005. In addition, follow-up sampling measurements were obtained from selected companies where exposure measurements had been collected prior to 1994, thereby providing a follow-up period of at least 10 years, to determine whether changes in exposure levels had occurred, with key staff being interviewed to identify factors that might be responsible for any changes observed.
Methods: Analysis of the temporal trend in exposure concentrations was performed using Linear Mixed Effect Models on the log-transformed NEDB data set and expressed as the relative annual change in concentration.
Results: For the NEDB wood dust data, an annual decline of geometric mean (GM) exposure of 8.1% per year was found based on 1459 exposure measurements collected between 1985 and 2003. This trend was predominantly observed in data from inspection visits (measurements collected on a mandatory basis by a Specialist HSE Inspector) (n = 1009), while data from representative surveys (measurements collected on a voluntary basis to provide information on current practices and exposures) remained relatively stable. Ten follow-up surveys in individual workplaces in 2004–2005 resulted in 70 new measurements and for each of the companies resurveyed, the GM of the wood dust exposure decreased between sampling surveys.
Conclusion: Analysis of the temporal trend in UK wood dust exposure concentrations revealed declines of 8% per annum. Interviews with key long-serving employees and management suggest that factors such as technological changes in production processes, response to new legislation, and enforcement agency inspections, together with global economic trends, could be linked to the downward trends observed.