Joint effects of smoking, noise exposure and age on hearing loss

BACKGROUND: Smoking has been shown to have adverse effects on hearing, but it's unclear whether smoking interacts with known causes of hearing loss such as noise exposure and ageing. AIMS: To examine the hypothesis that smoking, noise and age jointly affect hearing acuity. METHODS: This cross-sectional study was carried out in 535 male adult workers of a metal processing factory. Pure-tone audiometric tests were utilized to assess hearing loss. Noise exposure assessment was based on a job exposure matrix constructed with industrial hygienist scoring and job titles. Each participant answered questionnaires about socio-demographic, life-style, occupational and health-related data. Analysis of the possible underlying biological model was undertaken assessing departures from additivity using measures of the size of the interaction present. RESULTS: Age and occupational noise exposures were, separately, positively associated with hearing loss. For all the factors combined the estimated effect on hearing loss was higher than the sum of the effects from each isolated variable, especially for smoking and noise among those 20-40 years of age, and for smoking and age among those non-exposed to occupational noise. CONCLUSIONS: The synergistic effect of smoking, noise exposure and age on hearing loss, found in this study, is consistent with the biological interaction. Furthermore, it is possible that distinct ototoxic substances in the chemical composition of mainstream smoke may synergistically affect hearing when in combination with noise exposure, which needs to be examined in future studies.     

Occupational noise exposure and hearing loss: A study of knowledge,attitude and practice among Tanzanian iron and steel workers

Abstract

We assessed Knowledge Attitude and Practice (KAP) regarding occupational noise exposure, Noise-induced hearing loss, audiometry and use of hearing protection devices among iron and steel factory workers exposed to high noise level. A modified, validated, structured questionnaire was used to collect information from 253 male workers randomly selected from the four factories. The sum scores for each domain of KAP were computed. Scores above 75% were defined as good knowledge and positive attitude. For practice, scores of >50% were defined as good. Independent samples t-test and Chi-squared test were used to analyze association between KAP and continuous/categorical variables respectively. Majority of workers displayed poor knowledge and poor practice (94%), but 76% displayed a positive attitude. Most of the workers (86%) had never been provided with hearing protection devices. The mean scores for attitude and practice differed significantly between the four factories (one-way ANOVA, p?<?0.001). Implementation of hearing conservation program with provision of hearing protection devices are suggested.     

The health of the workers in a rapidly developing country: effects of occupational exposure to noise and heat

Occupational hygiene and safety have not been high on the agenda of industrial management in developing countries for a variety of reasons. This cross-sectional study was undertaken to assess the exposure to noise and heat, and to study the level of occupational hygiene practiced, at a foundry in a rapidly developing country (Dubai, United Arab Emirates). Audiometry, muscle cramps and visual acuity were measured in workers at a foundry and compared with the results from workers at a soft-drink bottling plant. Thermal stress, relative humidity, ventilation, illumination and noise levels were measured at different work units at the foundry and at the soft-drink bottling factory. Thermal stress index was high while relative humidity and ventilation were low at the foundry compared with the bottling plant. Noise levels were also high at the foundry, exceeding 90 dB at almost all work units except the fabrication workshop. Mild or moderate visual defects were observed among 31% of foundry workers, compared with 19% of the bottling plant workers.Muscle cramps were reported by 30% of all workers at the foundry, compared with 5% at the bottling plant. Visual disability was the highest among furnace operators and fabricators. Mean hearing disability was 8.69 +/- 1.08% among foundry workers, compared with 4.56 +/- 0.82% among bottling plant workers. The high thermal stress, noise levels and exposure to non-ionizing radiations at the foundry might have contributed to the higher frequency of muscle cramps and the greater hearing and visual disabilities, respectively, among these workers. Non-use of personal protective equipment and poor occupational hygiene and safety measures were also seen to affect eye and ear health adversely among the workers at the foundry.     

Hearing in young adults. Part I: The effects of attitudes and beliefs toward noise,hearing loss,and hearing protector devices

There is great concern regarding the development of noise-induced hearing loss (NIHL) in youth caused by high sound levels during various leisure activities. Health-orientated behavior of young adults might be linked to the beliefs and attitudes toward noise, hearing loss, and hearing protector devices (HPDs). The objective of the current study was to evaluate the effects of attitudes and beliefs toward noise, hearing loss, and HPDs on young adults’ hearing status. A questionnaire and an audiological test battery were completed by 163 subjects (aged 18-30 years). The questionnaire contained the Youth Attitude to Noise Scale (YANS) and Beliefs about Hearing Protection and Hearing Loss (BAHPHL). A more positive attitude or belief represented an attitude where noise or hearing loss is seen as unproblematic and attitudes and beliefs regarding HPDs is worse. Hearing was evaluated using (high frequency) pure tone audiometry (PTA), transient evoked and distortion product otoacoustic emissions. First, mean differences in hearing between the groups with different attitudes and beliefs were evaluated using one-way analysis of variance (ANOVA). Second, a χ² test was used to examine the usage of HPDs by the different groups with different attitudes and beliefs. Young adults with a positive attitude had significantly more deteriorated hearing and used HPDs less than the other subjects. Hearing conservation programs (HCPs) for young adults should provide information and knowledge regarding noise, hearing loss, and HPDs. Barriers wearing HPDs should especially be discussed. Further, those campaigns should focus on self-experienced hearing related symptoms that might serve as triggers for attitudinal and behavioral changes.     

Occupational induction of hypersensitivity after an accidental exposure to chloromethylisothiazolinone and methylisothiazolinone (CMI/MI) in an industrial worker.

A process worker in a paper chemical plant developed an immediate local dermal irritation and delayed bullous dermatitis due to induction of hypersensitivity following an accidental exposure to chloromethylisothiazolinone and methylisothiazolinone (CMI/MI) biocide. Contact allergy to the isothiazolinone mixture was confirmed by skin patch testing. The dermatitis healed in four weeks, and the worker was advised to avoid all CMI/MI containing products. In a one-year follow-up he did not present with any further skin symptoms. Preventive measures are important for avoiding induction of hypersensitivity to concentrated CMI/MI solutions in industrial workers.     

Sensorineural hearing loss (SNHL) as an adverse event following immunization (AEFI): Case definition & guidelines for data collection,analysis, and presentation of immunization safety data

This is a Brighton Collaboration case definition of the term “Sensorineural Hearing Loss” to be utilized in the evaluation of adverse events following immunization. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for Lassa Fever and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and define levels of diagnostic certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network.