Medical Surveillance of Compressed Air Work Support Service Personnel

A retrospective study of medical examination results and healthexperience of a group of 1030 persons who provided support servicesto a large compressed air work project, was aimed at determiningthe requirements for medical surveillance. The findings didnot justify a need for the rigorous examination schedules applicableto full-time compressed air workers and a more appropriate scheduleis proposed. ⁰Requests for reprints should be addressed to: F.J. O'Kelly, O.B.E. F.F.C.M. M.F.O.M., Occupational Health Division, Labour Department, Canton Road Government Offices, 5th Floor, Kowloon, Hong Kong.     

Dysbaric osteonecrosis in a compressed air tunnelling project in Hong Kong.

In the largest compressed air tunnelling project using the Blackpool Decompression Tables in Hong Kong, 912 men had radiological examination of major joints and 12 definite and 30 suspected cases of dysbaric osteonecrosis were detected by the compressed air physician. Distribution of the lesions was symmetrical and 43.1 per cent were juxta-articular. All the cases were asymptomatic. The infrequent occurrence of osteonecrosis in Hong Kong in general and in this project in particular suggests that the Blackpool Tables were relatively effective in preventing the disease. Definite and suspected cases were pooled together for the study of risk factors for osteonecrosis. Logistic regression analysis showed that the number of bends ever experienced, number of hours worked in the present contract, age and obesity were important independent risk factors. Because of the impossibility of a suitably long follow-up for all workers, the prevalence of osteonecrosis may be under-reported in Hong Kong.     

The emergence of urban ozone episodes in autumn and air temperature rise in Hong Kong

In recent years urban photochemical episodes accompanied by unusually high ozone concentrations have been observed in the urban area of Hong Kong every autumn season except 2003. These episodes always occurred in summer time since 1990, but starting in 2000 additional autumn episodes could be observed. During those episodes the ozone concentrations exceeded the Hong Kong Air Quality Objective and reached an hourly maximum of 332 μg m⁻³ in September 2005. The maximum ozone concentrations of both summer and autumn episodes seem to be on an upward trend. It is the objective of this paper to examine a possible role of the air temperature factor in the emergence of ozone episodes in autumn. Significant correlations could be found between the maximum hourly ozone concentrations and the maximum and mean air temperatures during autumn months whereas the association between ozone and particulates is weaker. Autumn air temperature data from the Hong Kong Observatory headquarters and two ozone monitoring sites had been compared for the period from 1989 to 2007. This analysis takes into account the ozone trend and the unfavorable conditions posed by decreasing solar radiation and increasing cloud cover. Mean temperatures for October and November at the Hong Kong Observatory headquarters as well as two ozone monitoring sites (Sha Tin and Tai Po) show a slightly upward trend for the period under investigation. The September values, however, show a slight negative slope. The overall upward trend for air temperatures in autumn occurs at a time when the mean air temperatures in Hong Kong have been on the rise for over 120 years from 1885 to 2007, amidst the global warming trend. It is believed that the air temperature increase may have contributed to the emergence of urban ozone episodes in autumn in Hong Kong in 2000. Related to this influence of air temperature on ozone are high background pollutant concentrations in Hong Kong, as indicated by the minimum PM₁₀ concentrations and the serious NO₂ pollution dominating the Pearl River Delta region.     

Silica Hazard of Caisson Construction in Hong Kong

Caisson construction work in Hong Kong generates considerablesilica dust from granite rock. A survey of 18 sites was aimedat assessing the hazard of silica dust and determining the prevalenceof silicosis among caisson workers. Data from 87 air samplesconfirmed high silica exposure in general with a severe exposurehazard for underground workers drilling rocks under conditionsof little or no wet suppression. Of 118 workers radiologicallyexamined, 12 cases of silicosis (including 6 cases of silico-tuberculosis)were found in underground workers (giving an overall prevalenceof 16 per cent in this group), and only in those with 10 to20 years of work experience. The occurrence of tuberculosisin another 6 underground and 2 surface workers appeared to behigher than expected. The findings confirmed a serious occupationalhealth hazard and the need for preventive action. Requests for reprints should be addressed to: T. P. Ng, Occupational Health Division, Labour Department, Hong Kong.     

Environmental and biological monitoring of occupational exposure to 1,1,1 -trichloroethane

Fifty workers involved in various degreasing and cleaning processesusing 1,1,1-trichioroethane (1,1,1-TCE) were studied with respectto personal and static exposures. In addition, end-of-shiftexpired air and venous blood samples were taken for analysisof the parent compound. Urinary samples were also obtained atthe same time for analysis of its metabolites - trichioroethanol(TCOH) and trichloroacetic acid (TCA). The results show thatopen/manual degreasing processes generate the highest environmentalsolvent levels (mean = 819.9 mg/m³; SD = 781.9 mg/m³) followedby jet-spray cleaning (mean = 460.5 mg/m³; SD = 292.4 mg/m³),vapour degreasing (mean = 365.3 mg/m³; SD = 279.9 mg/m³) andultrasonic degreasing (mean = 134.7 mg/m³; SD = 121.0 mg/m³).Personal exposure levels were well correlated with concentrationsof 1,1,1-TCE in end-of-shift expired air (r = 0.81) and venousblood samples (r = 0.88) but only moderately correlated withconcentrations of its metabolites in urine (r = 0.49 for TCOH;r = 0.58 for TCA). Static (area) samples were poorly correlatedwith the biological exposure indices studied.     

港九海底铁路建设中的减压病——工作条件与发病关系探讨

本文介绍香港九龙海底铁路建设中高气压作业与减压病发病情况。该工程有11条坑道,共计259 448个高压工作日,减压288 140人次,发生减压病1 534例。根据不同的工作压力,以暴露次数、高压工作日数及暴露4小时以上次数3种方法分别计算减压病发病率。结果表明:各种方法计算出的发病率都有随工作压力增高而上升的趋势,说明现用的减压表对不同的工作压力达不到同样的预防效果。本文还对3大主要工种和14个小工种的减压病作了分析。     

Associations between daily mortalities from respiratory and cardiovascular diseases and air pollution in Hong Kong, China

Objective: To investigate the association between ambient concentrations of air pollutants and respiratory and cardiovascular mortalities in Hong Kong.

Methods: Retrospective ecological study. A Poisson regression of concentrations of daily air pollutants on daily mortalities for respiratory and cardiovascular diseases in Hong Kong from 1995 to the end of 1998 was performed using the air pollution and health: the European approach (APHEA) protocol. The effects of time trend, seasonal variations, temperature, and humidity were adjusted. Autocorrelation and overdispersion were corrected. Daily concentrations of nitrogen dioxide (NO₂), sulphur dioxide (SO₂), ozone (O₃), and particulate matter <10 µm in aerodynamic diameter (PM₁₀) were averaged from eight monitoring stations in Hong Kong. Relative risks (RRs) of respiratory and cardiovascular mortalities (per 10 µg/m³ increase in air pollutant concentration) were calculated.

Results: Significant associations were found between mortalities for all respiratory diseases and ischaemic heart diseases (IHD) and the concentrations of all pollutants when analysed singly. The RRs for all respiratory mortalities (for a 10 µg/m³ increase in the concentration of a pollutant) ranged from 1.008 (for PM₁₀) to 1.015 (for SO₂) and were higher for chronic obstructive pulmonary diseases (COPD) with all pollutants except SO₂, ranging from 1.017 (for PM₁₀) to 1.034 (for O₃). RRs for IHD ranged from 1.009 (for O₃) to 1.028 (for SO₂). In a multipollutant model, O₃ and SO₂ were significantly associated with all respiratory mortalities, whereas NO₂ was associated with mortality from IHD. No interactions were detected between any of the pollutants or with the winter season. A dose-response effect was evident for all air pollutants. Harvesting was not found in the short term.

Conclusions: Mortality risks were detected at current ambient concentrations of air pollutants. The associations with the particulates and some gaseous pollutants when analysed singly were consistent with many reported in temperate countries. PM₁₀ was not associated with respiratory or cardiovascular mortalities in multipollutant analyses.

     

Addendum

Since this article was written a report in The Lancet (T. W.Hoskins et al. (1973) 1, 116) has also shown that an injectablevaccine using the A/Hong Kong strain gave substantial protectionagainst the A/England/42/72 variant.     

Preemployment medical examinations in a compressed air tunneling project in Hong Kong

One thousand workers intended to be employed in a compressed air tunneling project in Hong Kong had preemployment medical examinations for fitness to work in compressed air. Only 69.3% were declared fit and the overall unfit rate was 22.1%. The major disqualifying medical conditions were lung and heart abnormalities and chronic otitis media. Chest x-ray was found to be the most useful procedure in detecting the disqualifying conditions. The type I bends rate of the contract during the same period of examination was low: 1.39% at maximum working pressure of 2.45 kg/cm2, and there was no case of type II decompression sickness. Although many factors may affect the bends rate, it is suggested that the strict criteria adopted in the selection of workers might have contributed to the satisfactory outcome in the prevention of decompression sickness.     

TIME COURSE AND GENETIC VARIATION IN THE REGULATION OF CALCIUM CHANNEL ANTAGONIST BINDING SITES IN RODENT TISSUES DURING THE INDUCTION OF ETHANOL PHYSICAL DEPENDENCE AND WITHDRAWAL

Physical dependence was induced by ethanol inhalation in maleSprague-Dawley rats and, in parallel experiments, in two linesof mice (WSR and WSP) genetically selected for differentialseverity of ethanol withdrawal. In dependent rats [³H]nitrendipinebinding sites were significantly increased in cerebral cortex,cardiac and smooth muscle (vas deferens). Cerebral corticalmembranes were the first to show an increase, the B_max for nitrendipinebinding rising sharply after 3–4 days of ethanol administration,whereas binding sites in the other tissues increased after 5–6days. Nitrendipine binding affinity in all tissues was consistentlyreduced immediately preceding the rise in B_max to a new steadystate, but then returned to control values. Between 6 and 10days of ethanol exposure there was no further increase in theB_max for nitrendipine binding, and on removal of ethanol, thenumbers of nitrendipine binding sites fell precipitously tocontrol levels within 24 h of withdrawal. In the geneticallyselected mice, the up-regulation of nitrendipine binding sitesin cardiac membranes was significantly greater in the WSP line.This correlates with severity of physical signs of withdrawaland parallels previous results obtained in brain. The resultsare consistent with an increase in the synthesis and membraneinsertion of dihydropyridine sensitive calcium channel proteinsin several tissues during the induction of ethanol dependenceand suggest that in the brain this change may play a role inthe ethanol withdrawal syndrome.     

Studies on relationships between human and porcine influenza. 1. Serological evidence of infection in swine in Great Britain with an influenza A virus antigenically like human Hong Kong-68 virus

Serological evidence of infection of swine in Great Britain with an influenza A virus closely related to the human A/Hong Kong/68 (H3N2) variant was detected by a variety of serological tests. The Hong Kong/68 virus was first detected in man in Great Britain in August 1968 and was prevalent in the winters of 1968-69 and 1969-70. There was no evidence that swine had been infected with a Hong Kong/68-like virus before the appearance of the virus in man. The detection of virus-neutralizing antibody and high titres of neuraminidase-inhibiting antibody for Hong Kong/68 virus, and the production of precipitin lines corresponding to influenza A ribonucleoprotein and haemagglutinin and neuraminidase antigens of Hong Kong virus in immunodiffusion tests indicated that the swine sera contained antibody specific for the Hong Kong/68 virus. Evidence suggested that the infection of swine occurred in the early months of 1970. Clinical influenza among swine in Great Britain was not reported during the study period and there was no serological evidence of infection with “classical” swine influenzavirus strains.     

Influenza in East Africa, 1969-70

Very little information is available concerning the frequency of influenza in East Africa. Following recent outbreaks of influenza in Uganda, that were due to the A2/Hong Kong/68 virus, it was considered useful to obtain information relating to the prevalence of infection due to this virus and to the current strain of influenza B virus, not only in Uganda but also in the neighbouring territories of Kenya and Tanzania. The results of serological testing of sera showed that widespread outbreaks of influenza A2/Hong Kong/68 infection had occurred recently in all three territories, while there was evidence of sporadic infection in all territories by the current influenza B strain. Despite the favourable climate of East Africa, it is evident that widespread outbreaks of influenza can occur, and these may arise during the period of the year when influenza is rare in countries with temperate climates. Influenza can easily spread to other countries via air travellers to and from East Africa.     

Indoor Charcoal Smoke and Acute Respiratory Infections in Young Children in the Dominican Republic

The authors investigated the effect of charcoal smoke exposureon risks of acute upper and lower respiratory infection (AURIand ALRI) among children under age 18 months in Santo Domingo,Dominican Republic (1991–1992). Children living in householdsusing charcoal for cooking (exposed, n = 201) were age-matchedto children living in households using propane gas (nonexposed,n = 214) and were followed for 1 year or until 2 years of age.Fuel use and new episodes of AURI and ALRI were ascertainedbiweekly through interviews and medical examinations. Householdindoor-air concentration of respirable particulate matter (RPM)was measured in a sample of follow-up visits. Incidences ofAURI and ALRI were 4.4 and 1.4 episodes/child-year, respectively.After adjustment for other risk factors, exposed children hadno significant increase in risk of AURI but were 1.56 times(95% confidence interval: 1.23, 1.97) more likely to developALRI. RPM concentrations were higher in charcoal-using households(27.9 µg/m³ vs. 17.6 µg/m³), and ALRI risk increasedwith RPM exposure (10-µg/m³ increment: odds ratio = 1.17,95% confidence interval: 1.02, 1.34). Exposure to charcoal smokeincreases the risk of ALRI in young children, an effect thatis probably mediated by RPM. Reducing charcoal smoke exposuremay lower the burden of ALRI among children in this population. air pollution, indoor; biomass; charcoal; Dominican Republic; particulate matter; respiratory tract infections; smoke; wood     

ALCOHOL DEHYDROGENASE POLYMORPHISMS IN NATIVE AMERICANS: IDENTIFICATION OF THE ADH2*3 ALLELE

Alcohol dehydrogenase (ADH) polymorphisms were evaluated among95 Native American Mission Indians. Approximately equal frequenciesof ADH3^*1 and ADH3^*2 alleles were found. Twelve individualswere heterozygous for ADH2^*3, an allele previously identifiedonly in persons of African origin. None of the individuals withADH2^*3 alleles was of purely Native American descent, althoughnone had known African ancestry. These results suggest thatthese candidate genes deserve broader study among Native Americansand may provide increased understanding of the likely polygeniccontributions to alcohol-related disorders in this population.     

Engaging practitioners in research; time to change the values of practice rather than the way research is carried out?

The paper by Salmon et al.¹ challenges many of the agreed international‘norms’ for engaging practitioners in research projects.A group of UK researchers explore the reasons why only 67 outof 1934 family practitioners contacted agreed to take part ina study. We have all assumed that making time and resource availablefor practices, engaging practitioners in the design and prioritizationof research projects and increasing their own research skillswould increase the volume of research carried out in primarycare. Indeed, much of the past 14 years' initiatives in theUK, from primary care research networks, research capacity developmentprogrammes and now the UK Clinical Research Collaboration²,have been founded on these principles. Salmon et al. find thatit is not ‘time, money and lack     

Air pollution and hospital admissions for respiratory and cardiovascular diseases in Hong Kong

OBJECTIVE: To investigate short term effects of concentrations of pollutants in ambient air on hospital admissions for cardiovascular and respiratory diseases in Hong Kong. METHODS: Retrospective ecological study. A Poisson regression was performed of concentrations of daily air pollutant on daily counts of emergency hospital admissions in 12 major hospitals. The effects of time trend, season, and other cyclical factors, temperature, and humidity were accounted for. Autocorrelation and overdispersion were corrected. Daily concentrations of nitrogen dioxide (NO2), sulphur dioxide (SO2), ozone (O3), and particulate matter < 10 microns in aerodynamic diameter (PM10) were obtained from seven air monitoring stations in Hong Kong in 1994 and 1995. Relative risks (RR) of respiratory and cardiovascular disease admissions (for an increase of 10 micrograms/m3 in concentration of air pollutant) were calculated. RESULTS: Significant associations were found between hospital admissions for all respiratory diseases, all cardiovascular diseases, chronic obstructive pulmonary diseases, and heart failure and the concentrations of all four pollutants. Admissions for asthma, pneumonia, and influenza were significantly associated with NO2, O3, and PM10. Relative risk (RR) for admissions for respiratory disease for the four pollutants ranged from 1.013 (for SO2) to 1.022 (for O3), and for admissions for cardiovascular disease, from 1.006 (for PM10) to 1.016 (for SO2). Those aged > or = 65 years were at higher risk. Significant positive interactions were detected between NO2, O3, and PM10, and between O3 and winter months. CONCLUSIONS: Adverse health effects are evident at current ambient concentrations of air pollutants. Further reduction in air pollution is necessary to protect the health of the community, especially that of the high risk group.

 

     

Is there a typical Chinese diet and what are the health implications?

The results of a dietary survey performed on adults in the Hong Kong Chinese population in 1995 is examined in the light of published surveys for the Chinese populations in another region of Southern China, in Australia, and in an earlier Hong Kong Chinese population in 1987. The comparisons were made to document the extent of variability in the diets of the Chinese population and the implications for health. Among the Hong Kong Chinese population, there is an increase in the percentage energy from protein for men and women, and increase in percentage energy from fat and decreases in the percentage energy from carbohydrates for women between 1987 to 1995. Marked variations in dietary patterns exist in different geographical regions, probably as a result of differences in income, educational level, as well as cultural differences. Although the Chinese diet is considered to be beneficial in relation to coronary heart disease, the relatively high sodium and low calcium intake may predispose to other diseases such as stroke or osteoporosis.     

EFFECT OF CHRONIC ETHANOL ADMINISTRATION ON THIAMINE TRANSPORT IN MICROVILLOUS VESICLES OF RAT SMALL INTESTINE

The effect of long-term ethanol administration on the membranemechanism of thiamine entry in rat enterocytes was investigatedby using microvillous vesicles of small intestine. Experimentswere carried out in three groups of Wistar albino rats of bothsexes (290–400 g of initial body wt). Group I did notreceive any treatment, group II received 4.7 g of ethanol/kgbody wt (as a 50% hydroalcoholic solution) daily by gastricgavage for 35 days and group III (pair-fed controls) receiveda daily solution of saccharose (isoenergetic with the dose ofethanol administered to group II) by gastric gavage for 35 days.Ethanol or saccharose were administered in the morning and astandard diet was given throughout the treatment period. Allanimals were killed by decapitation 24 hr after the last administration,when the blood level of ethanol was virtually zero. Microvilloussmall intestinal vesicles were incubated with ³H-thiamine (³H-T)at 25°C and the amount of ³H-T taken up was measured bya rapid filtration method. Compared with data obtained in groupsI and III, chronic ethanol administration was found to inducea statistically significant decrease in ³H-T vesicular uptakeat 4 sec (determined at ³H-T concentrations ranging from 0.12to 7.5 µM) and a decrease in the apparent J_max (maximaltransport rate) value of the saturable component, without affectingthe apparent K_m (half-saturation concentration) value. These results indicate that in rats chronic ethanol administrationmay impair the intestinal absorption of thiamine by reducingthiamine entry into the enterocyte.     

2018年深圳和香港地区两起公共场所登革热暴发疫情对比

目的 对比分析深圳和香港地区两起公共场所登革热疫情流行特征和处置措施,融合优势以更好应对登革热暴发。 方法 收集两地登革热病例信息和蚊媒监测数据进行描述性流行病学分析,并对防蚊灭蚊措施进行对比。 结果 香港地区报告病例19例,疫情持续13 d,分布6个区,男女性别比为1：0.9。深圳20例,持续33 d,分布3个街道,男女性别比为1：0.82。两地年龄差别有统计学意义（Z=-2.855,P=0.004）。香港地区病例从出现症状到实验室确认时间间隔5.5~8.5 d,中位数7 d;深圳为1.5~5.4 d,中位数为2 d,差异有统计学意义（Z=-3.818,P < 0.001）。香港地区疫情第4 d宣布封闭感染场所30 d,灭蚊范围500 m,采用诱蚊诱卵器指数评价灭蚊效果。深圳第2 d宣布"封闭",灭蚊范围400 m,每3 d用布雷图指数、双层叠帐法监测。 结论 两地登革热疫情性质、规模、时间、场所相似,深圳处理措施更灵敏、快速,传染源早发现能力强,蚊媒监测方法更全面、频率更高。香港地区疫情信息公布、媒体风险沟通更主动,灭蚊措施更严格、专业。     

Validation of the International Prostate Symptom Score in Chinese males and females with lower urinary tract symptoms

Objectives

To evaluate the translation of the IPSS (Hong Kong Chinese version 1) and to assess the applicability, validity, reliability and sensitivity of the instrument in both males and females with LUTS in Chinese population.

Methods

The translation of the IPSS (Hong Kong Chinese version 1) was reviewed through back translation. Modifications were made, resulting in the development of The IPSS (Hong Kong Chinese version 2). The content validity was assessed by contend validity index. 233 subjects with LUTS were recruited in Hong Kong primary care settings for pilot psychometric testing. The construct validity was assessed by corrected item-total correlation and Pearson’s correlation test against ICIQ-UI SF, IIQ-7 and SF-12 v2. The reliability was assessed by the internal consistency (Cronbach’s Alpha coefficient) and test –retest reliability (Intraclass correlation coefficient). The Sensitivity was determined by performing known group comparisons by independent T-test.

Results

The content validity index for all items could reach 1. Corrected item-total correlation scores were ≥0.4 for four symptom questions (feeling of incomplete bladder emptying, intermittency, weak stream and straining). Overall, the total symptom score moderately correlated with ICIQ-UI SF. The quality of life score moderately correlated with the IIQ-7 but weakly correlated with SF-12 v2. Overall, the reliability of the IPSS (Hong Kong Chinese version 2) was acceptable (Cronbach’s Alpha coefficient?=?0.71, ICC of the symptom questions =0.8, ICC of the quality of life question =0.7). The symptoms questions and quality of life questions of the IPSS (Hong Kong Chinese versions 2) were sensitive in detecting differences between groups.

Conclusions

The IPSS (Hong Kong Chinese version 2) is a valid, reliable and sensitive measure to assess Chinese females and males with lower urinary tract symptoms. The IPSS quality of life question is more sensitive than the generic quality of life measure to differentiate subgroups.