Prolonged Occupational Exposure Research Articles

Surveillance for work-related audiological disease in the UK: 1998-2006

Noise-induced hearing loss (NIHL) from prolonged occupational exposure to noise continues to rank among the top worldwide work-related ill-health problems. To provide an overview of incident cases based on work-related audiological ill-health data collected over a 9-year period from occupational physicians (OPs), audiological physicians (APs), general practitioners and otorhinolaryngologists. Analysis of numerator data reported by physicians to surveillance schemes within The Health and Occupation Reporting network (THOR). The actual cases were multiplied by the sampling ratio to provide estimated numerator numbers, followed by calculation of incidence rates using denominator data derived from the Labour Force Survey and from surveys of participating OPs. Two thousand five hundred and eighty-two estimated cases (2584 estimated diagnoses) were received from OPs (Occupational Physicians Reporting Activity [OPRA]), and 2192 estimated cases (3208 estimated diagnoses) of work-related audiological ill-health were received from consultant APs [Occupational Surveillance Scheme for Audiological physicians (OSSA)] from 1998 to 2006. Cases where the causal agent was noise exposure (NIHL and tinnitus) made up of 95 and 97% of all cases reported to OPRA and OSSA, respectively. The annual average incidence rate for noise-induced audiological disorders was 7.9 [95% confidence interval (CI) 4.6-11.1] per 100 000 persons employed (OPRA) and 0.8 (95% CI 0.7-1.0) per 100 000 persons employed (OSSA). Workers with the highest incidence were older males employed in public administration and defence and the manufacture of metals. THOR data show that diagnoses related to work-related noise exposure (NIHL/tinnitus), as reported to THOR, remain important health problems, despite preventive measures being in place.

The Association between Prolonged Occupational Exposure to Paraphenylenediamine (Hair-dye) and Renal Impairment

Paraphenylenediamine (PPD) is widely used in hair dyes and cosmetic skin application. PPD intoxication following oral ingestion could be an important cause of ARF in Sudan, Morocco and the Indian Subcontinent. Repeated and prolonged exposure to PPD may also be associated with Chronic Kidney Disease (CKD). This is a cross-sectional study that covered six conveniently-chosen hairdressing saloons in Khartoum, Sudan. Hairdressers with regular professional exposure to PPD were evaluated for the presence of renal impairment (serum creatinine > or = 2 mg/dl) and other markers of kidney damage. The study included seventy-two females with a mean age of 40 +/- 8 years and a median duration of exposure to PPD of 6 years. Renal impairment, proteinuria and hematuria were observed in 14%, 26.4% and 41.1% of hair dressers, respectively. Hypertension, skin changes and bronchospasm were found in 19.4%, 38.9% and 22% of participants, respectively. Using pure forms of PPD significantly increased the risk of having elevated serum creatinine (OR 5.9; P = 0.02) and proteinuria (OR 9.8; P = 0.002) compared to manufactured forms with lower concentrations. Each additional year of exposure to PPD significantly increased the risk of having elevated serum creatinine (OR 1.3; P = 0.01), proteinuria (OR 1.4; P = 0.001) and hematuria (OR 1.1; P = 0.04). In this group of hairdressers with regular exposure to PPD, we observed high prevalence of renal impairment, proteinuria and hematuria. These findings were significantly associated with the use of pure forms of PPD and longer duration of exposure.

The Preventive Effects of Apolipoprotein Mimetic D-4F from Vibration Injury—Experiment in Rats

Hand-arm vibration syndrome (HAVS) is a debilitating sequela of neurological and vascular injuries caused by prolonged occupational exposure to hand-transmitted vibration. Our previous study demonstrated that short-term exposure to vibration can induce vasoconstriction and endothelial cell damage in the ventral artery of the rat's tail. The present study investigated whether pretreatment with D-4F, an apolipoprotein A-1 mimetic with known anti-oxidant and vasodilatory properties, prevents vibration-induced vasoconstriction, endothelial cell injury, and protein nitration. Rats were injected intraperitoneally with 3mg/kg D-4F at 1h before vibration of the tails for 4h/day at 60Hz, 49m/s(2) r.m.s. acceleration for either 1 or 3days. Vibration-induced endothelial cell damage was examined by light microscopy and nitrotyrosine immunoreactivity (a marker for free radical production). One and 3-day vibration produced vasoconstriction and increased nitrotyrosine. Preemptive treatment with D-4F prevented these negative changes. These findings suggest that D-4F may be useful in the prevention of HAVS.

Non-invasive diagnosis of chronic beryllium disease in workers exposed to hazardous dust in Israel

ObjectivesChronic beryllium disease (CBD) is caused by prolonged occupational exposure to beryllium and is characterised by various clinical presentations, mostly pulmonary. The inflammatory process involves non-caseous granulomas and proliferation of...

Neurophysiologic and Neurocognitive Case Profiles of Andean Patients with Chronic Environmental Lead Poisoning

This report presents case profiles of three siblings in a family of lead (Pb) glazing workers living in a Pb-contaminated Andean village who presented with extreme plumbism (blood Pb levels: 47 to 128 μg/dl) from childhood to adolescence. These cases are examples of persons who have chronic Pb poisoning as a result of prolonged occupational and environmental exposure in a Pb-glazing ceramic cottage industry in the study area. Using behavioral and physiological techniques for measuring the integrity of the peripheral and central auditory systems, including otoacoustic emissions, and replicated auditory brainstem electrophysiological potentials, the authors found normal auditory neurosensory function in each patient, thus ruling out hearing impairment as a basis for adverse neurocognitive outcomes. This finding is contrary to the prevailing view regarding the detrimental effects of Pb poisoning on the cochlear and auditory brainstem of children. Performance on tests of visual spatial intelligence and auditory memory/attention was below average in these patients, which may underlie their reported learning disabilities. In two of the cases, there was an improvement in cognitive performance following a lowering of PbB levels from chelation therapy and Pb prevention education, suggesting some level of reversibility of their neurocognitive deficits. Nevertheless, these case profiles suggest that if the patients persist in Pb-glazing activities, in spite of repeated chelation therapy and family counseling, they may continue to be re-intoxicated and remain at risk for learning disabilities and other neurological impairments.

POPs in breast milk: women's breast cancer risk

PurposePersistent organic pollutants (POPs) have become widespread pollutants and now represent a global contamination problem. The presence of POPs in human serum and adipose tissues have raised public concern regarding their possible role as important etiologic agents in the development of human cancer. This paper aims to investigate the extent of environmental contamination with pesticides and their association with women's risk of breast cancer.Design/methodology/approachVarious stages of carcinogenesis (initiation, promotion, progression), causes and risk factors associated with breast cancer are delineated. A possible mechanism of xenoestrogen and its association with breast cancer incidences in women is included. Recommendations for reducing breast cancer risks in women are also given.FindingsEpidemiological studies have revealed that persistent pesticide residues in human serum and adipose tissues may increase women's risk of breast cancer. Women are at a greater risk than men of pesticide exposure. The association between organochlorine compounds and breast cancer is a controversial issue and there exists an exigency to execute extensive worldwide epidemiological studies under identical conditions of detected compounds, blood sampling procedures and analytical techniques to achieve conclusive results.Practical implicationsWomen's risk of breast cancer associated with pesticide residues could be subjugated by avoiding prolonged occupational exposures, adopting precautionary measures, and changing lifestyle and dietary habits.Originality/valueThe paper shows that restrictions on the application of POPs and the avoidance of prolonged occupational exposure would result in lower concentrations of POP in blood, serum and adipose tissue, thus minimising women's risk of breast cancer.

Sclérodermie systémique diffuse liée à une exposition professionnelle au trichloroéthylène et perchloréthylène

Diffuse systemic sclerosis (DSS) is an autoimmune disease that is most often endogenous but which can also be induced by exogenous substances of occupational origin. We report a case of DSS involving prolonged intermittent occupational exposure to solvents (trichloroethylene [TCE] and perchloroethylene [PCE]). The disease was rapidly fatal with cardiac arrest secondary to myocardial fibrosis. In the event of exposure to TCE/PCE, we suggest more systematic prevention and diagnosis of DSS.

Using ZIP Code and GIS Studies to Assess Disease Risk

In several recent articles in EHP, investigators have attempted to link proximity to hazardous waste sites, as measured by geographic information systems (GIS) or ZIP codes, with increased incidences of various diseases. An implicit assumption in these studies is that proximity is a surrogate for exposure. However, numerous studies have demonstrated that the presence of chemicals in an individual’s environment does not necessarily translate into a dose. For example, Stehr-Green et al. (1988) found that

Pandemic influenza planning: Shouldn’t swine and poultry workers be included?

Recent research has demonstrated that swine and poultry professionals, especially those who work in large confinement facilities, are at markedly increased risk of zoonotic influenza virus infections. In serving as a bridging population for influenza virus spread between animals and man, these workers may introduce zoonotic influenza virus into their homes and communities as well as expose domestic swine and poultry to human influenza viruses. Prolonged and intense occupational exposures of humans working in swine or poultry confinement buildings could facilitate the generation of novel influenza viruses, as well as accelerate human influenza epidemics. Because of their potential bridging role, we posit that such workers should be recognized as a priority target group for annual influenza vaccines and receive special training to reduce the risk of influenza transmission. They should also be considered for increased surveillance and priority receipt of pandemic vaccines and antivirals.

Evaluation of individuals with known or suspected noise damage to hearing

The diagnosis of hearing impairment due to noise damage is based on the assessment of the type and level of exposure to noise, the patient's medical history, and a clinical and audiometric evaluation. The risk for developing hearing loss increases substantially when the equivalent sound pressure levels of noise exceed 80dB(A). Very high exposures (above 100dB(A)), usually to impulse noise (e.g. fireworks), can result in acoustic trauma. In this case, sensorineural hearing loss develops immediately after exposure and is frequently accompanied by tinnitus. It can be unilateral or asymmetrical, and temporary (temporary threshold shift – TTS) or permanent (permanent threshold shift – PTS). Noise-induced hearing loss (NIHL) that develops after prolonged occupational exposures to relatively moderate levels of noise (85–100dB(A)) is a bilateral, symmetrical, or almost symmetrical, and permanent sensorineural hearing loss progressing slowly over the years of employment. The most dynamic rise in PTS can be seen du...

Grand Rounds: Could Occupational Exposure to n -Hexane and Other Solvents Precipitate Visual Failure in Leber Hereditary Optic Neuropathy?

ContextLeber hereditary optic neuropathy (LHON) is a maternally inherited loss of central vision related to pathogenic mutations in the mitochondrial genome, which are a necessary but not sufficient condition to develop the disease. Investigation of precipitating environmental/occupational (and additional genetic) factors could be relevant for prevention.Case presentationAfter a 6-month period of occupational exposure to n-hexane and other organic solvents, a 27-year-old man (a moderate smoker) developed an optic neuropathy. The patient had a full ophthalmologic and neurologic investigation, including standardized cycloergometer test for serum lactic acid levels and a skeletal muscle biopsy. His exposure history was also detailed, and he underwent genetic testing for LHON mitochondrial DNA mutations. The patient suffered a sequential optic neuropathy with the hallmarks of LHON and tested positive for the homoplasmic 11778G → A/ND4 mutation. Routine laboratory monitoring revealed increased concentrations of urinary 2.5 hexandione (n-hexane metabolite) and hippuric acid (toluene metabolite) in the period immediately preceding the visual loss.DiscussionIn a subject carrying an LHON mutation, the strict temporal sequence of prolonged appreciable occupational exposure followed by sudden onset of visual loss must raise a suspicion of causality (with a possible further interaction with tobacco smoke).RelevanceIn this article, we add to the candidate occupational/environmental triggers of LHON and highlight the need for appropriate case–control (and laboratory) studies to validate the causal effect of mixed toxic exposures.

Axonal Degeneration with Unusual Lesions of the Myelin in an Occupational Neuropathy

A 35-year-old man had prolonged occupational exposure to lead carboxylate, triethylbenzene, xylene, and dichloromethane, when he developed a subacute predominantly sensory neuropathy. Ultrastructural examination of a peripheral nerve biopsy showed axonal degeneration and unusual lesions of the myelin, with Schwann cell sequestration of vesicular and lamellar debris. Biochemical analysis of lead in a frozen peripheral nerve specimen revealed no significant difference between the propositus and a control. The authors were unable to find any similar peripheral nerve lesions in the literature dealing with neurotoxic chemicals. Any of the several organic solvents could have equally caused the neuropathy and may have been potentialized by the other chemicals.

Recent developments in manganese speciation

Manganese is an abundant element in the environment and widely used throughout industry. Although manganese has relatively low toxicity, in chronic overdose or prolonged occupational exposure, it can cause severe disruption to the central nervous system. This article illustrates the requirements for manganese speciation and reviews the analytical methods applied to such studies, including electroanalytical techniques and hybrid systems, such as liquid chromatography or electrophoresis coupled to inductively coupled plasma spectrometry.

A four-year follow-up study on subjective symptoms and functional capacities in workers using hand-held grinders.

Fifty-three grinders in the metal industry were re-examined 4 years after their first examination. Information about age, occupation, daily vibration exposure, drinking and smoking habits, and presence of subjective symptoms such as vibration-induced white finger (VWF), and numbness and pain in the fingers was collected during the first and second examination. Cold provocation test (10 degrees C/10 min) was also employed to evaluate disturbances in the peripheral circulatory and peripheral nerves in all subjects. The frequency-weighted vibration acceleration of various types of hand-held tools was measured. There was no subject with VWF at the first examination; however, during the course of follow-up, two cases (3.8%) of VWF with latent interval of more than 25 years were diagnosed. Prevalence of numbness in the fingers and shoulder stiffness was significantly higher at the second examination. When the prevalence of subjective symptoms was tested by the subjects' total operating time (TOT) during the 4-year follow-up period, those whose TOT was equal to or more than 2500 hours showed higher prevalence compared to the other subgroup. The paired values of recovery rate of finger skin temperature and vibration sensation threshold after the cold water immersion test were significantly different at the first and second examination. On average, the diminution of hand-grip force during the 4-year follow-up course was 7.4%; the difference being significant at 0.01 level. Significant differences in the paired data of pinching power and tapping ability could be detected. The frequency-weighted vibration acceleration of various tools was in the range of 1.1-4.6 m/s2. It was concluded that: (1) prolonged occupational exposure to the vibration of hand-held grinding tools should be considered as a risk factor causing disturbances in the hand-arm system of the operators; (2) the results of recovery rate of finger skin temperature and the vibration sensation threshold seemed to be appropriate indicators for the assessment of peripheral vascular and peripheral nerve disturbances in workers exposed to hand-arm vibration; and (3) to reduce the subjects' physical stress, attention should be paid to ergonomic factors.

Renal cell cancer correlated with occupational exposure to trichloroethene.

A previous cohort-study in a cardboard factory demonstrated that high and prolonged occupational exposure to trichloroethene (C2HCl3) is associated with an increased incidence of renal cell cancer. The present hospital-based case/control study investigates occupational exposure in 58 patients with renal cell cancer with special emphasis on C2HCl3 and the structurally and toxicologically closely related compound tetrachloroethene (C2Cl4). A group of 84 patients from the accident wards of three general hospitals in the same area served as controls. Of the 58 cases, 19 had histories of occupational C2HCl3 exposure for at least 2 years and none had been exposed to C2Cl4; of the 84 controls, 5 had been occupationally exposed to C2HCl3 and 2 to C2Cl4. After adjustment for other risk factors, such as age, obesity, high blood pressure, smoking and chronic intake of diuretics, the study demonstrates an association of renal cell cancer with long-term exposure to C2HCl3 (odds ratio 10.80; 95% CI: 3.36-34.75).

Occupational physical activity and long-term risk of musculoskeletal symptoms: a national survey of post office pensioners.

The objective of this work was to address the relationship between physical activity in the workplace and subsequent musculoskeletal pain syndromes. We performed a survey of 5,042 men and women aged 70-75 years, selected from the retirement population of a large national employer (the post office). Subjects were sent a short postal questionnaire enquiring about all occupations held for at least 1 year, the physical activities performed in those jobs, and about recent rheumatic symptoms. The 1-month period prevalence of rheumatic symptoms ranged from 19.9% for hip pain or stiffness in men to 50% for knee pain or stiffness in women. Symptoms were more common in women than men at all sites and there were significant (P < 0.001) associations between symptoms at different sites. Obesity was significantly (P < 0.001) associated with the risk of pain or stiffness at the knee and hip. Prolonged occupational exposure (20+ years) to heavy lifting was associated with hip pain (RR = 1.5; 95% CI = 1.2-1.8); and prolonged exposure to working with arms elevated was associated with an increased risk of shoulder pain (RR = 1.4; 95% CI = 1.2-1.6). Tall stature (P = 0.003) and heavy lifting (P < 0.001) were both associated with increased risks of low back pain among men. This survey confirms the high prevalence of musculoskeletal symptoms observed in previous population-based studies. Associations between occupational activities and musculoskeletal symptoms were specific for activity type and skeletal site involved. Our results imply that the adverse effects of these occupational activities can be found many years after cessation of exposure.

Renal cell carcinomas in trichloroethene (TRI) exposed persons are associated with somatic mutations in the von Hippel-Lindau (VHL) tumour suppressor gene.

Renal cell carcinomas (RCC) develop as a consequence of somatic mutations of the von Hippel-Lindau (VHL) tumour suppressor gene. Recent epidemiological studies show that high and prolonged occupational exposures to trichloroethene (TRI) are associated with an increased incidence of RCC. Tumour tissues from 23 RCC patients with occupational histories of very high TRI exposure were analysed for somatic mutations within the VHL gene. DNA was isolated from microdissected tumour cells, amplified by polymerase chain reaction (PCR), and analysed in single strand conformation polymorphism (SSCP) and sequencing. RCC tissues of all 23 TRI exposed persons analysed thus far showed aberrations of the VHL gene, with 30% having aberrations in exon 1, 44% in exon 2, and 26% in exon 3. By comparison to much lower reported VHL mutation frequencies of 33-55% in TRI-unexposed RCC patients, these results indicate a specifically high mutation frequency at the VHL gene in TRI-exposed RCC patients; four of these aberrations have thus far been confirmed as VHL mutations by sequence analysis. This finding indicates the VHL gene being a susceptible and specific target in TRI induced renal carcinogenesis. Furthermore, the frequent involvement of exon 2 identifies potential 'hot spots' for this carcinogen. In addition to the available epidemiological studies the results are now further proof for human renal carcinogenicity induced by high occupational exposures to TRI.

Occupational exposure and incidence of chronic respiratory symptoms among residents of Cracow followed for 13 years

We analyzed the relationship between incidence rates of chronic respiratory symptoms over 13 years and occupational exposure during the first five years of follow-up. The study group contained 1132 males and 1598 females, 19 to 60 years of age, randomly selected from residents of Cracow, Poland. The data was collected in three surveys conducted in 1968, five and 13 years later. Prolonged occupational exposure (i.e. reported in the initial survey and 5 years later) to dusts doubled the odds for the appearance of chronic phlegm and attacks of breathlessness in all men, and of chronic bronchitis in men aged 41 to 50, initially free of the symptom. In women, this exposure doubled the odds for new chronic cough and for chronic bronchitis. Prolonged exposure to chemicals doubled the incidence rates of attacks of breathlessness and dyspnea in all women and of chronic bronchitis in women with the lowest level of education. Prolonged work in variable temperatures doubled the risk of wheeze in women. The effects of discontinuation or start of exposure during the initial 5 years of the study were also seen on the incidence rates of the symptoms but were less pronounced. The detected effects of occupational exposure were not modified by cigarette smoking or living in areas of the city with various levels of air pollution. This longitudinal analysis confirms the results of cross-sectional studies which have indicated deleterious effects of even moderate occupational exposures on respiratory symptoms.

Familial mesothelioma: Review and family study

To date, with few exceptions, primary attention to the etiology of malignant mesothelioma has been focused on environmental factors. However, several reports of familial aggregations of mesothelioma strongly support the supposition that host factors, in concert with environmental exposure, particularly asbestos, may contribute etiologically to an as yet unknown fraction of occurrences of this disease. However, in evaluation of familial mesothelioma, it is important to consider the possibility of household exposure to asbestos. We report a family in which two brothers with prolonged occupational asbestos exposure manifested malignant pleural mesotheliomas of similar histology.

A multivariate analysis of the risk in chronic obstructive lung disease (COLD)

This study was undertaken to assess the validity of cluster analysis for stratifying patients with severe COLD into homogenous subgroups in view of further prospective studies.To this aim, physiological measurements and questionnaire data were obtained from 532 outpatients with severe COLD (e.g. a 1 sec forced expiratory volume (FEV1) below 1.5-1/sec). The model variables selected for the partition in cluster were FEV1, PaO2, response to bronchodilators and heart rate.Two subgroups of patients were identified by the analysis: cluster I with significantly greater physiological impairment than cluster II. The comparison of the prevalences of the variables outside the model between the 2 clusters showed, in fact, that cluster I had a significantly higher prevalence of subjects with heavy smoking (p < 0.01), prolonged occupational exposure (p < 0.05), low body weight (p < 0.05), recent hospitalizations for respiratory troubles (p < 0.02) and emphysema (p < 0.01).In conclusion, cluster analysis based on few physiological variables was able to identify, among patients with severe COLD, those with poorer general conditions and higher exposure to specific risk factors, for whom a worse prognosis of life can be expected.The advantages of cluster analysis in comparison to other techniques of classification in this kind of patient is discussed.