Our results revealed that factors that were associated with the ward environment and administration were important in nosocomial outbreaks of SARS. The lessons learned from this study remain very important and highly relevant to the daily operation of hospital wards if we are to prevent nosocomial outbreaks of other respiratory infections in the future.

The temporal-spatial spread of SARS in the ward was consistent with airborne transmission, as modeled by use of computational fluid dynamics. Infected health care workers likely acted as secondary sources in the latter phase of the outbreak.

Chinese women in Hong Kong have among the highest incidence and mortality of lung cancer in the world, in spite of a low prevalence of smoking. We carried out this population-based case-control study to evaluate the associations of previous lung disease and family cancer history with the occurrence of lung cancer among them. We selected 212 cases that were newly diagnosed with primary lung cancer, and randomly sampled 292 controls from the community, frequency matched by age group. All the cases and controls were lifetime nonsmokers. We estimated the main effects of preexisting asthma, pulmonary tuberculosis, pneumonia, chronic bronchitis, and family lung/all cancer history, using unconditional logistic regression, accounting for various potential risk factors and confounders. All of the previous lung diseases, except chronic bronchitis, were related to an elevated risk for lung cancer, and the association with asthma was significant. Those who had more than one previous lung disease tended to be at higher risk than those with only one of them. Positive family history of any cancer was associated with over 2-fold risk than negative family history. The joint effect of positive history of previous pulmonary diseases and positive family cancer history appeared to be additive, indicating the two factors acted independently. The results support an etiological link of preexisting lung disease and family cancer history to the risk of lung cancer.

BackgroundNoise-induced hearing loss (NIHL) is a major concern in the non-manufacturing industries. This study aimed to investigate the occupational noise exposure and the NIHL among Chinese restaurant workers and entertainment employees working in the service industry in Hong Kong.MethodsThis cross-sectional survey involved a total of 1,670 participants. Among them, 937 were randomly selected from the workers of Chinese restaurants and 733 were selected from workers in three entertainment sectors: radio and television stations; cultural performance halls or auditoria of the Leisure and Cultural Services Department (LCSD); and karaoke bars. Noise exposure levels were measured in the sampled restaurants and entertainment sectors. Each participant received an audiometric screening test. Those who were found to have abnormalities were required to take another diagnostic test in the health center. The “Klockhoff digit” method was used to classify NIHL in the present study.ResultsThe main source of noise inside restaurants was the stoves. The mean hearing thresholds showed a typical dip at 3 to 6 KHz and a substantial proportion (23.7%) of the workers fulfilled the criteria for presumptive NIHL. For entertainment sectors, employees in radio and television stations generally had higher exposure levels than those in the halls or auditoria of the LCSD and karaoke bars. The mean hearing thresholds showed a typical dip at 6 KHz and a substantial proportion of the employees fulfilled the criteria for presumptive NIHL (38.6%, 95%CI: 35.1–42.1%). Being male, older, and having longer service and daily alcohol consumption were associated with noise-induced hearing impairment both in restaurant workers and entertainment employees.ConclusionExcessive noise exposure is common in the Chinese restaurant and entertainment industries and a substantial proportion of restaurant workers and entertainment employees suffer from NIHL. Comprehensive hearing conservation programs should be introduced to the service industry in Hong Kong.

Aims: To study the agreement between audiometric test results measured in non-soundproof environments at the worksite, and in a soundproof booth. Methods: In a cross sectional prevalence study on noise induced hearing loss, 885 transport workers whose hearing thresholds were measured by a standard audiometric test method in non-soundproof environments at the worksite were identified to have some hearing loss (>25 dB), and were retested in a soundproof booth. Results: At 4-8 KHz, the mean of the absolute differences in hearing threshold obtained by these two methods was 2 dB or less. When the proportions of hearing loss ( >30 dB for any frequencies at 3-8 KHz, or >90 dB for three low frequencies at 0.5-2 KHz, or >90 dB for three high frequencies at 3-6 KHz) were compared, considerable differences existed. A much better agreement was obtained when the criteria for hearing loss as measured in the field test under non-soundproof conditions were relaxed by 5 dB. At 4 KHz, the difference between the proportion of subjects with hearing loss as measured in the field and that as measured in the booth was the smallest. The kappa statistic was highest at 3 and 4 KHz. Conclusions: Audiometric test results conducted in non-soundproof environments in the field are comparable to those obtained in a soundproof environment among transport workers with a hearing loss of >25 dB. The hearing threshold at 4 KHz appears suitable for the estimation of the prevalence of hearing loss when appropriate adjustments are made in the diagnostic criteria. Sound is a form of energy generated by vibration. It can be characterised by its frequency, measured in Hertz (Hz), which represents the number of vibration cycles per second, and its intensity, a measure of energy level, expressed in watts per square metre (W/m 2 ). Sound intensity level is measured by a logarithmic scale, in decibels (dB), because the human ear can detect a wide range of intensities. A reference intensity of 10 −12 W/m 2 , corresponding to the human hearing threshold, is arbitrarily set as 0 dB. Noise, defined as unwanted sound, is one of the most common occupational and environmental hazards. Prolonged exposure to excessive noise causes a sensorineural hearing deficit that begins at the higher frequencies (3-6 KHz). This deficit is commonly described as "noise induced hearing loss" (NIHL).It has been shown that once exposure to damaging noise levels is discontinued, further significant progression of hearing loss will stop.1 This implies that the early detection of NIHL through audiometry among high risk workers is useful in the prevention of further hearing losses. Periodic screening for hearing impairment among the workers exposed to excessive sound levels is therefore an important component of hearing conservation. Ideally, audiometric measurements are made in a soundproof environment at different frequencies and intensities to detect the hearing threshold of the subject at the respective frequencies. However, this environment is not always available in field surveys, e...