Study of heat exposure in the work environment in Jeddah.

The present work was conducted to define the magnitude of the problem of heat exposure in Jeddah and the role of both the climatic and the industrial factors on the total heat load. Indoor heat exposure was studied in an industrial complex of 5 plants for cables' manufacturing. Outdoor heat exposure was studied in shaded and unshaded operations in Jeddah Islamic Port (JIP). The heat exposure parameters, including air temperature (Ta), wet bulb temperature (Tw), and globe temperature (Tg), as well as the wet bulb globe temperature (WBGT) heat stress index, the relative humidity and the air velocity, were assessed at representative locations. Results of the study indicated that: (a) the levels of heat exposure exceeded the TLV in mostly all the work areas where no air-conditioning is provided. (b) the ambient heat is the factor contributing most to the heat load both in summer and in winter. (c) the radiant heat from furnaces and hot metal rolling and milling adds more heat load to the work environment in specific operations. An outline of a control strategy has been suggested, emphasizing evaporative engineering heat control, work and hygienic practices and auxiliary cooling clothing.

Study of noise pollution in Jeddah schools.

Noise was measured in classrooms of a stratified random sample of 20 schools in Jeddah. The mean "Average" Leq levels (60-89.2 dB[A]) highly exeed the recommended maximum levels (42-55 db[A]). Noise is higher in the classes adjacent to the streets than in those facing the school courts, particularly at the busy areas, and in the schools of the busy areas than of the semi-busy and of the residential areas. But, noise is lower in the pre-cast structure schools than in the concrete schools due to the better insulating characteristics of the former, and the higher noise induced by the window-type air conditioning units used in the latter. However, the students' recreational activities have equal noise impact in the primary, intermediate and secondary schools. It has been recommended to build schools in low-noise background locations, to reduce transmitted noise by proper city planning, traffic engineering and improved construction characteristics, and to properly select and maintain the air conditioning systems.

Analytical study of the safety records of a leading seaport in the GCC.

The pertinent records of the year 1411 H (1990/1991) for a leading seaport of a member state of GCC were examined for appraising safety performance there. The recorded accidents during this year included: 270 accidents without injuries, 58 first-aid accidents and 138 work injuries (leading to absence off work) and 4 fatalities. The injury frequency rate there (3.41) is comparable with similar agencies, while the severity rate (725.2) is considerably higher. Collision of transport, lifting and material handling equipment represents the major type of work accident (58.9%), while the highest injury rates occurred in maintenance and operation of marine equipment, followed by loading and unloading, then housekeeping. Meanwhile, the rate of accidents showed considerable increase a--during summer months, b--during the peak months of the Gulf war followed by "re-export" of war equipment, c--in the middle days of the week, d--during the 4th and 8th hours of shift, with a sharp decrease during and after lunch hours, and e--among workers performing highly technical jobs; however decreased by gaining experience with the long duration of employment. Most of the accidents could be prevented by proper training of workers and appropriate supervision, since their cause was unsafe acts due to lack of attention and/or of supervision.

Child labour in Egypt. I. Occupational and socio-economic aspects.

The present study comprised 1000 child and young workers in small and medium-size industries in Alexandria, as well as 250 control subjects. Almost all young workers work for more than 40 hours/week and suffer from fatigue. Workers' family needs rather than the lack of family care is the responsible factor for sending the child to work, and the economic problems seem to be the underlying factor for all other problems of child labour. Work improves labourers' socio-economic status and smoking habit, and provides a chance for their personal contacts and interactions, which are reflected on their level of intellectual capabilities; however, it has some impact on their food habits affecting their achievement of balanced diet; and no drug addiction exists among all the studied subjects. Noise and dust represent the main occupational exposures (84.4% and 55.8% respectively), followed by exposure to heat (25.3%), vapors and gases (10.4%) and biological materials (9.0%), and nearly 2/3 of the workers have combined exposures. Work injuries occurred to 18.4% of the workers and 7.4% had more than one injury during employment; however, nearly 1/3 of the injuries required absenteeism off work and/or hospitalization. The injuries have been typically related to industrial operations, occurring mostly to hands and fingers (80.4%), and are mainly attributed to lack of training (63.0%). The health services presented to the workers are very poor. The study has been concluded by recommending making the work safe, free from hazards, and ergonomically fit to children, providing educational and training services, covering young workers by social security, and revising legislation of child labour.

Appraisal of work hazards and safety in the industrial estate of Jeddah.

An environmental study for the appraisal of work hazards and safety in Jeddah Industrial Estate (JIE), Saudi Arabia has been conducted. The study is based upon a representative (stratified random) sample of 44 enterprises, including 52 plants and employing 5830 workers.Nearly 2/3 of the workers have heat exposure, orginating from climatic heat and heat dissipated from industrial operations, while exposure to noise is slightly less, and is attributed to noisy operations and machinery and to lack of meticulous maintenance; both exposures are mild in most of the plants and moderate in some. Mild exposures to nonionizing radiations (UV and IR) and to deficient illumination occur in 25% and 19.2% of the plants studied. Respiratory exposure to chemical agents (organic and inorganic dusts, metal fumes, gases and vapours - including asphyxiants, irritants, liver and nervous system offenders and acid and alkali mists) occurs in 75% of the plants, particularly in the medium-size enterprises plants; however, is mainly mild with a few moderate and severe exposures. Skin absorption contributes to absorption of chemical agents in 29% of the plants, and direct skin contact to chemicals (particularly to lubricating oils) occurs in 81% of the plants.Meanwhile, only eight plants, out of the 32 plants where controls for physical hazards are required (51.2%), apply engineering controls, and even in a few of these plants the efficiency of the control measures has been rated 'bad'. A few of them provide personal protective equipment, and even no maintenance to this equipment is provided.The level of safety is better in the large plants than in the small and medium-size plants; the safety score is the best in the recently established plants, while is the worst in the plastic industry, which is relatively old. The appraisal of fire protection is better than that of the safety, due to efficient supervision of the General Directorate of Civil Defense (GDCD). However, most of the safety problems are managerial and are preventable.First aid is present in all enterprises, as required by the Saudi Labor Laws; however, an in-plant medical service is present in 75% of the large enterprises, in 31.6% of the medium-size and in only 17.6% of the small enterprises. Also, satisfactory medical, accidents and absenteeism records exist in only 15.9% of the enterprises; safety supervision exists in 27.3, and safety education exists in 91% of them, while no environmental monitoring is carried out in any enterprise. Sanitation facilities exist in satisfactory numbers in most of the enterprises; however, their maintenance is poor in most of them, due to lack of hygienic supervision. All enterprises dispose of their liquid wastes into the JIE sewerage system without any treatment, while the solid wastes are collected by the city authorities in 56.8% of them; both wastes are anticipated to cause environmental pollution problems.

Study of noise pollution in Jeddah hospitals.

The present study was conducted on a sample of 6 hospitals in Jeddah to investigate the status of noise pollution there, and as related to community background noise, operational activities, hospital size and operational concepts (public vs private). Generally, the levels of noise in the clinics, patient rooms, offices, waiting areas and corridors significantly exceed the recommended standard. The noise levels in the machinery rooms significantly exceed the levels in offices, waiting areas and corridors which, in turn, significantly exceed the levels in clinics and patient rooms. Background community noise has a little impact on indoor noise due to the construction characteristics of the hospitals' buildings. However, "operational noise" from machinery and from the move of public (patients, attendants and employees) significantly contribute to indoor noise. Proper site location, city planning, traffic engineering, building construction, equipment selection, construction and equipment maintenance, and system management have been recommended for the abatement of hospital noise pollution.

A comparative environmental and medical study of dust exposure in jute and cotton mills in Burma.

Jute is extensively cultivated and processed in Burma, as well as "lower-grade" cotton. This study was conducted there to compare dust exposure in jute and cotton mills, to study the acute and chronic effects of dust exposure on workers, and to establish exposure-response relationship. A sample of 799 male and female workers in two jute mills and two cotton textile mills, as well as a control group of 153 matching subjects, was examined, and dust exposure in the work environment was evaluated. Very high dust concentrations existed in the early stages of jute processing and sorting, which were reduced when jute fibers got cleaner, as in drawing and spinning, and were related to the grade of the processed fiber. Much lower concentrations of dust existed in the cotton mills, but exceeded the TLV (ACGIH) only in opening and cleaning and in carding operations. However, byssinosis occurred only in workers exposed to cotton dust, particularly among males, and its prevalence was related to the level and duration of dust exposure. Chronic bronchitis, cough and wheezing occurred at higher rates among all workers than in the control, while irritation to nose and throat, eyes and skin prevailed only among jute workers. A significant reduction in FVC, FEV1.0 and PEF (before and during shift) was observed in workers compared to control subjects, and was related to workers' exposure and age; however, this reduction was not related to symptoms of different respiratory conditions. "Cheroots" smoking was found to be an important potentiating factor in the occurrence of non-specific respiratory diseases and reduction in FEV1.0, particularly among jute workers.

Role of histamine in the aetiology of byssinosis. II. Lung histamine concentrations in guinea pigs chronically exposed to cotton and flax dusts.

Data presented in this study support the finding that cotton and flax dusts contain agents which potentiate the formation or accumulation of histamine or both in the lungs of guinea pigs exposed to dust, and that such agents are present at much higher levels in cotton dust than in flax dust. The potentiating effect may be through the recruitment of mast cells into the lung. Both cotton and flax dusts contain methylating enzyme inhibitory agents, whereas cotton dust also contains agents that inhibit histaminase activity; flax dust contains agents potentiating histamine activity. These agents working together result in the accumulation or depletion of histamine observed in the different groups of animals exposed to either cotton or flax dust in this study.

Role of histamine in the aetiology of byssinosis. I Blood histamine concentrations in workers exposed to cotton and flax dusts.

The formation or the accumulation, or both, of histamine in the lungs may be potentiated by agent(s) present in cotton dust at higher level(s) than in flax dust and negligible in cottonseed dust. It has been suggested that such potentiation may be due to the activation of the ability of the lung to produce histamine and/or produce or recruit mast cells; this may present an acceptable explanation of the mechanism by which the propagation of the chronic effect of the dust proceeds in cotton and flax workers. Histamine accumulated in the lung over the weekend is released on exposure to dust causing the symptoms of byssinosis. The difference in the rate of histamine metabolism relative to the rate of histamine formation in byssinotic subjects leads to a more prolonged histamine accumulation than in symptom free subjects, with the consequent appearance of the symptoms of byssinosis. Continuous exposure to dust, without weekend interruption, leads to equivalent rates of histamine formation and metabolism with non-considerable histamine accumulation in the lungs and consequent absence of the symptoms of byssinosis.

An environmental and medical study of byssinosis and other respiratory conditions in the cotton textile industry in Egypt.

This study was conducted in a typical Egyptian textile plant located in Alexandria. Male workers from all operations (N = 506) were examined and their dust exposures were assessed. Results showed that airborne dust concentrations were very high and that the plant fraction is mostly concentrated in respirable dust. Byssinosis prevailed in 21% of workers in opening and cleaning sections and in 13% in carding and combing rooms, but was found in none of the workers in drawing, twisting, and spinning operations, in only 1.1% in weaving, and in 3.1% of workers in other "auxiliary" occupations. The rare prevalence of byssinosis among the latter workers' groups was attributed to the workers' continuous exposure without fixed weekend interruption, the personal and family history of exposure to cotton, the low proportion of plant materials in dust evolved in related operations, the fine quality of Egyptian cotton, and/or the population characteristics of Egyptian workers. Reduction in FEV 1.0 at the end of the first work shift after absence from work occured more often than byssinosis, which indicates the importance of this test for the early detection of effects of cotton dust exposure. It is suggested that a nationwide study in the cotton textile industry is indicated.

Some observations on epidemiologic studies in Egyptian gins, cotton pressing plants and cottonseed oil extraction plants.

The follow-up studies presented in this report wee conducted to evaluate the impact of the relative technical improvements that took place in the cotton processing industries of Egypt in the last 10-15 years on the health of the workers. Results have indicated tha: 1) the health status of the workers has been relatively improved; however, their work environment is far from being safe. 2) The prevalence of byssinosis and reduction in FEV1 during the first day of work after the weekend are related to the duration of exposure, level of dustiness and content of plant debris in dust. 3) Chronic effect of exposure to cotton dust, demonstrated as reduction in predicted FVC, develops in workers continuing exposure for long durations, even if the classic symptoms of byssinosis and reduction in FEV1 do not occur. 4) Women workers are more liable to be affected by cotton dust exposure than the men. 5) "Cottonseed dust" may not be a "byssinnogenic" dust; however, it is capable of producing ventilatory function effects similar to those produced by cotton dust.

Role of family susceptibility, occupational and family histories and individuals' blood groups in the development of silicosis.

A previous investigation has shown that family susceptibility and occupational and family histories have a decisive role in the development of byssinosis among workers exposed to flax dust. Results of investigation of silicosis in 814 male workers exposed to silica-bearing dust showed that family susceptibility has an important role in the development of silicosis among examined workers, and workers whose fathers had an occupational history of exposure to silica-bearing dust were more resistant to the development of the disease than those with non-exposed fathers. The degree of consanguinity of parents and individuals' blood groups, also, have a role. Workers with cousin parents were relatively highly susceptible to the development of silicosis as well as workers with blood groups "O" or "AB". It has been concluded that the investigated factors might have a role in the development of other occupational diseases and further investigations are indicated.