Facteurs prédictifs de la surdité professionnelle induite par le bruit chez les travailleurs des centrales électriques / Predictive factors of occupational noise-induced hearing loss in power plant workers

Analyser le lien entre la surdité professionnelle induite par le bruit et les caractéristiques socioprofessionnelles des travailleurs. Méthodes: C'était une étude prospective et analytique, par enquête avec évaluation audiométrique du 1er août au 30 septembre 2020, concernant 92 travailleurs des deux centrales de la Société Nationale d'Electricité de N'Djamena.Les tests de khi2et de corrélation de Pearson étaient utilisés à la recherche d'un lien entre la surdité due au bruit et les facteurs socioprofessionnels; une différence était dite statistiquement significative si p <0,05. Résultats: L'échantillon était constitué de 96% d'hommes. L'âge variait de 23 à 64 ans avec une moyenne de 38,7 ± 9,0 ans. Quarante-sept (51%) employés étaient formés sur la sécurité en milieu professionnel. Les agents de quarts représentaient 45% des cas (n=41). La durée d'exposition moyenne au bruit était de 10,8 ± 8,5 ans. Le port des équipements de protection individuelle était régulier dans 86% des cas (n =79). La surdité professionnelle a été observée dans 55% des cas (n=51). L'âge (p <10-3) et la durée d'exposition au bruit (p=0,002) étaient les facteurs associés significativement à la surdité. Conclusion: L'âge et l'ancienneté sont les facteurs prédictifs de la surdité chez les travailleurs exposés aux bruits des centrales électriques de N'Djamena.

Occupational lung disease among Basotho ex-miners in a large outreach medical assessment programme

Background: Current initiatives in southern Africa to medically assess former migrant miners for silicosis and tuberculosis, including statutory and lawsuit derived compensation programmes, require burden of disease information. nObjective: To use clinical information collected on ex-miners examined at the Occupational Health Service Centre (OHSC) in Lesotho, operated under the Tuberculosis in Mining Sector in Southern Africa (TIMS) project, to measure the burden of lung disease and respiratory impairment. Methods: Demographic, occupational and medical history information, chest radiology, spirometry, GeneXpert testing for tuberculosis, and pulse oximetry outcomes were analysed, and descriptive summary measures calculated, in a group of ex-miners examined in 2017 and 2018. Results: The study sample comprised 2 758 Basotho former underground miners, with median age of 62 years and median length of service of 28 years. Among ex-gold miners (n = 2 678), disease prevalence was high: radiological tuberculosis (consistent with previous or current disease) 60.9%, silicosis 42.5%, HIV 30.7%, silicotuberculosis 25.7%, and current active tuberculosis 6.8%. Of those with tuberculosis diagnosed microbiologically, 6.7% had no radiological evidence of tuberculosis and 54.1% did not report cough. Conclusion: The findings have public health and compensation implications. There are large numbers of ex-miners with potentially compensable disease under both the statutory system and a settlement trust set up following litigation. This overlaps with a tuberculosis-HIV co-epidemic which requires screening and treatment for tuberculosis and HIV, and managing a considerable disability and care burden on families and the Lesotho health system. Coordinated planning and substantial resources are needed for these programmes to do justice to their mandates

Causes of stress in vehicle manufacturing employees and perceptions of the effectiveness of a stress management intervention programme

Background: Stress has become a part of everyday life for most employees. Studies have shown the negative effect that stress has on employee wellbeing. Stress management intervention (SMI) programmes are commonly implemented by organisations to reduce work-related stressors, as well as to assist employees to cope with and minimise the impact of stress. Objectives: We aimed to explore the causes of stress at a vehicle manufacturing company, and the perceptions of employees about the effectiveness of an SMI programme. Methods: A qualitative interpretive approach was followed, using a case study design. The research was conducted at a vehicle manufacturing company in Pretoria, South Africa; eleven purposively sampled permanent white- and blue-collared employees who had participated in an SMI programme were included. Data were collected from personal interviews and a focus group discussion. The data were analysed using the ATLAS.ti software. Results: Some of the causes of stress in the workplace, identified by the participants, were company ethics and culture, interpersonal conflict, management style, deadlines, workload, type of job, job profiles, job insecurity, incompetence of employees, lack of resources, and remuneration. Most participants (90.9%) evaluated the SMI as being very effective. Conclusion: The causes of stress amongst workers are multifactorial. Effective SMIs can assist to alleviate stress and to equip employees with skills to manage stress. This promotes a healthy workforce and increases productivity. If SMIs are not implemented effectively, there might be loss in productivity, increased absenteeism, and deteriorating health in the workforce

Prevalence and predictors of low back pain in a Southern Nigerian hospital

Background: Low back pain (LBP) is the most common musculoskeletal disease in adults. The data on LBP from Sub-Saharan Africa are inadequate. The aim of this study was to assess the prevalence and analyze the predictors of LBP among hospital staff in a Nigerian tertiary hospital. Materials and Methods: The study participants were recruited using an opt-in approach, with the aim of including representative numbers from each professional cadre. Each participant gave formal consent. Ethical clearance was obtained. Results: Five hundred and sixty-three participants with the mean age of 36.0 ± 8.3 years and 62% female were interviewed. The point prevalence of LBP was 234 (42% [95% confidence interval [CI]: 37%­45%]). Profession was a significant predictor of LBP (P = 0.001) ­ nurses (53% [95% CI 43%­63%]), administrative officers (49% [95% CI 40%­59%]), engineers (50% [95% CI 24%­76%]), and health information staff (50% [95% CI 26%­75%]) had the highest prevalence. In univariate regression, female gender, increasing age, body mass index ≥25 kg/m2, and frequently adopting a bending posture, were significantly associated with LBP, while in multivariate regression, only the female gender was a significant predictor. Conclusion: The pattern of both the professions at risk, due to the well-known mechanisms of poor ergonomics, and the marked risk for the female gender, in the hospital setting, suggest underresourced work and societal environments as the underlying factors-more research is needed

Allergies respiratoires professionnelles liées à l'exposition à la poussière de farine de blé: cas de 05 boulangeries de la ville de Porto-novo

Objectif : Prévenir les allergies respiratoires professionnelles chez les travailleurs exposés à la poussière de farine de blé dans les boulangeries de la ville de Porto-Novo. Méthode : Il s'est agi d'une étude transversale descriptive conduite d'Octobre à Décembre 2014 dans 5 boulangeries de la ville de Porto-Novo. A travers un échantillonnage à deux degrés, nous avons sélectionné d'une part de façon aléatoire 5 boulangeries des 32 de la ville et d'autre part de façon exhaustive recruter 51 travailleurs des 5 boulangeries. Il a été procédé à un examen physique (auscultation pulmonaire et examen oto-rhinolaryngologique) systématique de tous les travailleurs interviewés. Analyse des données : Les données ont été enregistrées et analysées avec le logiciel EPI info version 3.5.3. Les résultats obtenus ont été compilés dans des tableaux de fréquence simple. Résultats : La grande majorité des travailleurs sont de sexe masculin (90,2%). La plupart des travailleurs ont un âge compris dans la tranche de 31 et 50 ans (47,1%) et une ancienneté comprise entre 1 à 9 ans (47,2%). Les travailleurs sont concentrés au niveau des postes de : façonnage (68,7%), pétrissage (49,1%) et enfournage (39,2%). Les procédés et pratiques générateurs d'importantes poussières selon les travailleurs sont : le fleurage (88%), la vidange des sacs à farine dans le pétrin (80%), l'usage du balai pour le nettoyage (41,2%) et le pétrissage (19,6).. Les symptômes respiratoires dont se plaignent souvent les travailleurs sont : éternuement (82,4%), rhume/écoulement nasal (58,8%), toux (37%) et bronchorrhée (27,5%). Ces symptômes apparaissent chez les travailleurs le plus souvent après un délai d'exposition compris entre 1 et 9 ans et plus de la moitié des cas (57,1%) dans la tranche d'âge de 31-50ans. 2/3 des cas d'asthme sont survenus chez les travailleurs dans cette fourchette d'âge. Conclusion : La farine est désormais reconnue comme étant le premier allergène professionnel. Il s'avère important d'adopter une démarche de prévention adéquate du risque qu'elle constitue afin de garantir la santé et la sécurité aux travailleurs

Work-related musculoskeletal disorders and predisposing factors among commercial motorcyclists in Ibadan North Local Government Area, Nigeria

Background: Studies on the prevalence of work-related musculoskeletal disorders (WRMSDs) among motorcyclists in sub-Saharan Africa are scarce.Objective: This study aimed to investigate the prevalence of WRMSDs and the predisposing factors among commercial motorcyclists operating in Ibadan North Local Government Area, Oyo State, Nigeria.Methods: Information was obtained from 122 (of 200) motorcyclists using a structured questionnaire which elicited information on the respondents' demographic characteristics, work experience, and predisposing factors to, and possible causes of, WRMSDs.Results: The response rate was 61.0%. The age range of the 122 participants was 15 - 55 years. One hundred and thirteen (92.6%) of the motorcyclists reported WRMSDs and 66.4% of all respondents worked for 6 - 10 hours daily. Lower back complaints were most commonly reported. WRMSDs were significantly associated (p < 0.05) with age, marital status, education, years of experience, hours spent at work daily, and days spent working per week. Conclusion: The prevalence of WRMSDs was high among these workers. Age, marital status, educational qualification and work behaviour were risk factors

Occupational skin disorders in a subset of Nigerian hairdressers

Introduction: hairdressing is associated with a wide range of disorders. This is particularly true in the African hairdresser, who is saddled with the responsibility of 'taming' the rather difficult-to-manage African hair, and is thus exposed to a wide range of chemical, biological and physical materials in the hair grooming process. We therefore sought to determine the prevalence and pattern of occupational skin disorders among hairdressers in Ibadan, one of the oldest and largest cities in Nigeria.Methods: this was a cross sectional study of hairdressers conducted in 2013 in Ibadan, Nigeria. Hairdressers and their apprentices were interviewed using a structured questionnaire, following which a thorough physical examination was performed to identify any skin disorder.Results: a total of 226 hairstylists were recruited. The prevalence of occupational skin disorders in the study was 68.13%. The prevalence of specific skin disorders was 32.74% for nail disorders; 28.75% for traumatic skin disorders; and 2.64% for hand dermatitis.Conclusion: there is a high prevalence of occupational skin disorders among hairdressers, and this may have personal and public health implications

Analyse des facteurs d'exposition des ouvriers spécialisés d'une entreprise togolaise du Bâtiment et Travaux Publics (BTP) aux lombalgies communes en 2015

La lombalgie commune constitue un problème de santé majeur en milieu professionnel. Objectifs : Décrire les caractéristiques épidémiologiques des ouvriers, déterminer le taux de prévalence de la lombalgie commune, identifier les facteurs de risques professionnels et décrire les conséquences. Méthodes : L'étude, transversale et analytique a été conduite du 1er février au 30 mai 2015. Elle a inclus les maçons, menuisiers et ferrailleurs répondant aux conditions de sélection. Les variables ont été recueillies à partir du questionnaire nordique modifié et adapté au contexte de l'étude. Résultats : Sur un effectif de 675 ouvriers spécialisés, 158 étaient éligibles (35,3%). La moyenne d'âge était de 33,1 ± 6,9 ans, avec des extrêmes de 20 et 58 ans ; ils étaient à 98,10% des hommes ; La moyenne d'ancienneté professionnelle était de 9,3 ± 6,6 ans, la durée hebdomadaire moyenne de travail de 44,8 ± 2,9 heures. Le taux de prévalence était de 82,3% ; en effet, 130 ouvriers sur 158 étaient lombalgiques. Les facteurs individuels étudiés n'étaient corrélés à la lombalgie. La catégorie professionnelle des menuisiers, la position debout et la durée hebdomadaire de travail prolongée au-delà de 40 heures étaient significativement liés à la lombalgie. Des 130 ouvriers lombalgiques, 43 ont bénéficié d'un arrêt de travail (33,8%). Le nombre total de journées de travail perdues a été estimé à 380. La durée moyenne d'arrêt de travail était de 15,2 ± 4 jours. La lombalgie a imposé une restriction d'activités courantes chez 49,2% des ouvriers et chez 7 (5,4%) un changement de poste. Conclusion : La prévalence des lombalgies communes est très élevée chez les ouvriers spécialisés dans cette entreprise de BTP. Elles sont positivement corrélées à des facteurs professionnels qui doivent faire l'objet des mesures de prévention

Occupational Injuries among Workers in a Welding Company within Mangaung Metropolitan Municipality

A questionnaire survey was conducted among 37 welders and 21 fitters (exposed group) and 30 office workers (unexposed group) employed by a welding company located in the Mangaung Metropolitan Municipality. The objective was to calculate and describe the prevalence of occupational injuries among these workers and to compare the frequencies of injuries. A total of 87 injuries were reported by workers. The most common injuries sustained were burns (n=29); cuts (n=24); eye injuries inflicted by foreign objects (n=19); electric shock (n=8); arc eyes (n=4); and bone fractures (n=3). Most occurred on the hands (n=57). More workers in the exposed group sustained injuries than in the unexposed group. It is necessary to implement safety measures in order to reduce the prevalence of injuries

Fate of Outstanding COIDA Occupational Disease Claims Following Closure of the Western Cape Provincial Medical Advisory Panel in 2008 : An audit

Background and objectives: The Western Cape Provincial Medical Advisory Panel (PMAP) was established in 2004 in terms of Section 70(1) of COIDA. A primary function was to improve the efficiency of medical assessment of occupational disease claims. The PMAP was closed by the Compensation Commissioner in 2008. This audit aimed to determine the fate of claims outstanding at the time of closure. Methods: A total of 68 claims outstanding in April 2008 were followed up by telephone; email and/or internet to determine what proportion had progressed or; if accepted; had resulted in a permanent disablement compensation payment. Results: Of the 68 claims; 31 (44) were confirmed as having progressed. Of these; payment of permanent disablement awards could be confirmed in only 15 claims (22). The remaining 56 either showed no progress or no longer had a record in the COIDA system. Those stages of the claims process that had previously been aided by PMAP functioning had deteriorated in efficiency. Conclusions: Overall; the low proportion of outstanding claims finalised and awarded is consistent with inefficiency in claims handling of occupational disease; a finding echoed by recent complaints about general Compensation Fund performance from both healthcare providers and parliamentary investigation

Prevalence and severity of pterygium among commercial motorcycle riders in south eastern Nigeria

Background: Pterygium is common among outdoor workers who are daily exposed to sunlight and dust due to repeated conjunctival /corneal drying and microtrauma especially in the tropics. Commercial motorcyclists in Nigeria are outdoor workers who spend the greater part of the day outdoors under the intense heat and dust characteristic of this part of the world and would therefore be largely predisposed to developing this conjunctival disorder. Objective: The aim of this study is to determine the prevalence and severity of pterygium among these workers and relate these findings to their duration of work. Methods: A cross sectional study with a multi stage random sampling design was used to choose the 615 subjects enrolled in the study. Results: The prevalence for pterygium was 19.3 (206 eyes) with stage 1 occurring mostly (52) followed by stage 2(46). Pterygium was common among riders who had been riding for 5 years or less. The relationship between duration of riding and pterygium severity was significant (p=0.009). This prevalence was unaffected by the use of regular sun glasses (p=0.188). Conclusion: A strong relationship exists between commercial motorcycle riding and development of pterygium not affected by using regular sunglasses. We recommend that helmets with full face shields and/or proper UV protected riding goggles where the helmets have no face shield be enforced by the regulation bodies so as to reduce the prevalence of these disorders

Taking an occupational history: its value in avoiding a misdiagnosis

Taking an occupational history is crucial for identifying an occupational disease; avoiding a misdiagnosis and directing the further medical and administrative management of a patient who also happens to be a worker. There are two components of an occupational history; a set of screening questions and a set of in-depth questions which can provide information on the occupational relatedness of a disease. Occupational presentations such as polymer fume fever and its consequences as presented in this paper can be missed in the absence of an occupational history. Reinforcing training in occupational history-taking teaching in undergraduate medical training programmes can contribute to improved diagnosis of occupational disease in clinical practice; and consequent improvements in the detection and reporting of occupational diseases

Analyse de 87 dossiers de maladies a caractere professionnel colliges au CHU de Yopougon a Abidjan de 1990 a 2009

Les auteurs rapportent un ca s de pheochro- mocytome ectopique. Cas clinique : patiente de 29ans; hypertendue connue depuis 8ans et diabetique depuis 7ans; admise en urgence pour perte de connaissance. L'examen clinique a montre une pression arterielle a 190/130mmHg; un pouls a 116 battements/minute et un Glasgow a 7 sans deficit hemi corporel. L'examen du fond d'oil a mis en evidence des signes de retinopathie hypertensive stade III. Le dosage plasmatique de la normetanephrine etait de 3917ng/l (normale170) et celui de la metanephrine de 59ng/l (normale73). Le scanner abdominal a montre un processsus tumoral tissulaire para-renal anterieur et polaire superieur gauche; mesurant sur une coupe axiale 73;8 X 51;3mm. Le diagnostic de pheochromocytome a ete pose. Le traitement a consiste a une exerese de la tumeur. L'evolution est favorable. Conclusion : le pheochromocytome para renal est une cause rare d'hypertension arterielle maligne

The effect of occupationally related low back pain on functional activities among male manual workers in a construction company in Cape Town; South Africa

This study determined the prevalence as well as the effect of occupationally-related low back pain on the functional activities of workers in a construction company in Cape Town. A cross-sectional; descriptive survey using a validated questionnaire was carried out. The questionnaire comprising demographic data; low back pain symptoms information; functional limitations scale and the participation restriction scale was used as a closed ended interview guide. Workers suffered physical; emotional; fi nancial and functional problems with 41.5 reporting sickness absence. Lifting and bending were the most affected activities associated to low back pain (p0.05) while walking/running; recreational activities and carrying out of everyday tasks were among the restricted activities. The one year prevalence of low back pain was 25 ; comparable with that of developed countries. Occupationally-related low back pain is a challenge among construction workers which they perceive to cause serious functional activity limitation. All stakeholders must be procured for the prevention and management of occupationally-related low back pain in order to prevent functional activity limitations among construction workers. Physiotherapists should raise the levels of awareness and monitor construction activities on site in order to prevent disability at primary level

Prevalence of neck and back pain among dentists and dental auxillaries in South-western Nigeria

Dental health workers like other workers have occupation related health problems and hazards which include neck and low back pain. Previous studies have shown that the prevalence and location of pain may be influenced by posture and work habits and as well as demographic factors. The aim of this study was to determine the prevalence of neck and back problems among dentists and dental auxillaries in private and government dental hospitals in south western Nigeria. Structured self administered questionnaire was sent to dentist and dental auxillaries by randomly selecting 3 out of the 6 state capital from the southwestern Nigeria. Participants included those in private clinics; teaching hospitals and general hospitals. The questionnaire was composed of respondents biodata; questions about specific information on neck and back pain and routine practice posture while working at chairside. The total number of properly filled questionnaire was 210 with a male to female ratio of 1.04:1. Respondents included 147 dentists; 37 dental surgeon assistants (DSA); 14 dental therapists and 12 dental technologists. Prevalence of back and neck pain among the respondents was 88.1and 81.9respectively. Among the male respondents; the prevalence of back pain was 86.9and 89.3in female while for neck pain ; the prevalence was 83.2in male and 80.6in female. Within the different professional groups; the prevalence of back pain was highest among the DSA(89.2); closely followed by the dentists(88.4); then therapists(85.7) and least among the technologists(83.3). For neck pain; the prevalence was highest among therapists followed by technologists ; dentists and least among the DSA. More females missed work due to back and neck pain than males. There is therefore the need to address ergonomic issues and change the way dentistry is practiced

Exposure to Human Immunodeficiency Disease. What Precautions for the Healtcare Professional?

: The Human Immunodeficiency Virus (HIV) epidemic is more pronounced in sub- Saharan Africa. The ever-increasing prevalence of HIV infection and the continued improvement in clinical management has increased the likelihood of these patients being managed by healthcare workers. The aim of the review was to assess current literature on the risks of transmission of HIV infection and protection of the healthcare worker.Methods: A literature review was performed using MEDLINE articles addressing `human immunodeficiency virus'; `HIV'; `Acquired immunodeficiency syndrome'; `AIDS'; `HIV and Surgery'. We also manually searched relevant surgical journals and completed the bibliographic compilation by collecting cross references from published papers.Results: Transmission is by contamination with body fluids for example needle-stick injury and blood splashes. The risk of HIV transmission from patient to healthcare worker always exists. The risk of transmission is very small and depends on the type of discipline and type of procedure. Hollow needles are more dangerous than suture needles. Sero-conversion is; however; very minimal. Universal precautions are emphasised. In case of needle-stick injury or splash it is important that affected healthcare workers take post-exposure prophylaxis.Conclusion: Occupational HIV transmission is lower than that for other infections. However; protection of all health care personnel should be the prime objective. Universal infection control guidelines must be accepted and strictly enforced. A prompt response to blood contact is crucial and post-exposure prophylaxis is essential

Morbidity and Mortality Patterns of Nigerian Petroleum Oil Refining and Distribution Industry

Aimed at unraveling the nature and extent of health effects and impacts of occupational exposures in the Nigerian petroleum refining and distribution industry; this study probed the morbidity and mortality partterns of this industry using oral interviews; questionnaires responses and secondary data from the industry. Results revealed that workers of this industry suffer from wide range of disease conditions involving virtually all body organs/systems; manifesting with varied symptoms that often brought them to the industry-based plant clinic. Questionnaire responses by the staff showed that Bad eye sight (16.3); sexually transmitted diseases (8.9); hypertension (8.8); musculo-skeletal health effects including chronic and intermittent back/low back pain (8.6); neck and shoulder pain (2.7) and chest pain (2.0)); sleeping/relaxing difficulty (8.0); recurring headache (6.4); reduced hearing/noise-induced hearing loss (NIHL) (6.4); erectile dysfunction (weak erection)(5.3); breathing difficulty (3.9); Road transport accident (3.1); Peptic Ulcer disease (PUD)(3); Diabetes mellitus(2); prostate enlargement (0.5); Tonsil enlargement (0.1); pulmonary disease (0.1) and renal disease (0.1) were some of the symptoms/diseases or complaints by the staff. Documentations at the plant clinic however; revealed that malaria/functional disorders (33.3); respiratory disorders (13.5); Musculo-skeletal/ Rheumatic diseases (14.0); High blood pressure (10.9); gastrointestinal disorders (9.1) and Diabetes mellitus (4.1) were among the leading clinical conditions responsible for higher clinical attendance at the plant clinic. Genito-Urinary disorder (3.3); Eye/Visual Disorder (2.7); ear; nose and throat Problems (1.9); Occupational dermatitis (0.3) and Non-Occupational Skin Disorders (2.3) are among the reckonable entries that made the list of ailments suffered by the staff. Mortality statistics showed that a total of 79 deaths occurred within the period under review. Retroviral disease (21) topped the list of cause of death; followed by road/water transport accidents (16.5) and cardiac related diseases (13.9). Virtually all body organ/system-related pathologies including those of the lungs (5.1); endocrines (presence of diabetes mellitus (3.9); kidneys (3.8); liver (2.5); blood (leukaemia 2.5); and CNS (1.3) contributed to the cause of death. These results indicate that oil and gas work environment predisposes to sundry health effects that might hasten staff death. This calls for a comprehensive review of the contents of the occupational health services as to guarantee total health protection for the workers of this critical sector of the Nigerian economy

An exploratory examination of poor construction work practices: Opportunities for ergonomic interventions in the Western Cape

Construction activity is ergonomically challenging. In the study reported in this paper; the ergonomics challenges that construction artisans and their assistants encounter are examined in detail using naturalistic enquiry. The findings reveal unfavourable and repetitive poor work practices. It is contended that these practices; when extrapolated over the working life of the artisans and their assistants could arguably lead to musculo-skeletal syndromes and associated absenteeism. Recommendations for ergonomic interventions are made as solutions to these health consequences

The prevalence of occupational asthma and rhinitis among woodworkers in south-eastern Nigeria

Wood dusts are known to cause respiratory disorders like rhinitis and asthma. This study was therefore done to determine the magnitude of the problem among woodworkers in south-eastern Nigeria exposed to high level of wood dust.Five hundred and ninety one woodworkers were selected using a stratified random sampling. The prevalence of woodworkrelated rhinitis and asthma were then observed in the study population. Also the peak expiratory flow rate (PEFR) of each woodworker was obtained. The prevalence of occupational rhinitis was 78%, while that of asthma was 6.5%. As period of woodwork increased the prevalence of rhinitis and asthma increased (rhinitis: χ2 trend = 53.015, df = 1, P = 0.000). For asthma, χ2 trend =19.721, df = 1, P = 0.000). Also the PEFR significantly became low with increasing years of exposure to woodwork (χ2 trend = 75.965, df = 1, P= 0.000). In conclusion the prevalence of rhinitis and asthma in woodworkers was high and significantly increased with years of working as a woodworker