Assessment of personal protective equipment use and occupational exposures in small industries in Jeddah: Health implications for workers

Small-scale industries account for a large proportion of jobs and play a vital role in most countries’ economic growth and prosperity. Due to the very low use of personal protective equipment (PPEs), employees are exposed to numerous physical, chemical, and accidental hazards in small-scale industries. PPEs are very effective in minimizing occupational injuries, accidents, and other hazards which otherwise result in substantial manpower and financial losses. The study objective was to assess the availability and use of PPEs as well as self-reported occupational exposures among workers in surveyed small industries in Jeddah. The study involved 102 workers from 28 small-scale industries (vehicle repair, welding, and paint). A survey was conducted to gather data of socio-demographic characteristics, self-reported occupational exposures, and frequency of PPEs used by workers. The occupational exposures (never exposed, sometimes exposed and always exposed) were reported in percentages including; noise exposure (19.6, 73.5 and 6.9%); dust/smoke exposure (9.8, 69.6 and 20.6%); vapors/fumes exposure (11.8, 60.8 and 27.5%); and direct sunlight (43.1, 56.9 and 0%), respectively. The reported use of different PPEs in descending order was; knee joints mats (50%), welding shields (50%), safety glasses (33.3%), gloves (27.5%), face masks (26.5%), safety shoes (10.8%) and earplugs/ muffs (8.8%). On the basis of this study findings, hand hygiene and general OSH awareness like interventions can be developed which will help in minimizing workplace exposures among small-scale industry workers.     

In vivo activation of human immunodeficiency virus type 1 long terminal repeat by UV type A (UV-A) light plus psoralen and UV-B light in the skin of transgenic mice.

UV irradiation has been shown to activate the human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) in cell culture; however, only limited studies have been described in vivo. UV light has been categorized as UV-A (400 to 315 nm), -B (315 to 280 nm), or -C (less than 280 nm); the longer wavelengths are less harmful but more penetrative. Highly penetrative UV-A radiation constitutes the vast majority of UV sunlight reaching the earth's surface but is normally harmless. UV-B irradiation is more harmful but less prevalent than UV-A. In this report, the HIV-1 LTR-luciferase gene in the skin of transgenic mice was markedly activated when exposed to UV-B irradiation. The LTR in the skin of transgenic mice pretreated topically with a photosensitizing agent (psoralen) was also activated to similar levels when exposed to UV-A light. A 2-h exposure to sunlight activated the LTR in skin treated with psoralen, whereas the LTR in skin not treated with psoralen was activated after 7 h of sunlight exposure. The HIV-1 LTR-beta-galactosidase reporter gene was preferentially activated by UV-B irradiation in a small population of epidermal cells. The transgenic mouse models carrying HIV-1 LTR-luciferase and LTR-beta-galactosidase reporter genes have been used to demonstrate the in vivo UV-induced activation of the LTR and might be used to evaluate other environmental factors or pharmacologic substances that might potentially activate the HIV-1 LTR in vivo.     

In vivo release of non-neuronal acetylcholine from human skin by dermal microdialysis: effects of sunlight, UV-A and tactile stimulus

Non-neuronal acetylcholine (ACh) is expressed in epithelial, endothelial and immune cells. For example, the in vivo release of ACh from the human skin pretreated with botulinum toxin has recently been demonstrated. In the present experiments the effects of light (sunlight and solar radiation by a commercial UV-A applier) and of a tactile stimulus on the release of non-neuronal ACh were investigated. Release of ACh from the proximal and distal shin, i.e. anterior tibial region, was measured by dermal microdialysis in 20 min samples over a time period of at least 140 min. Control experiments were performed in a dark room throughout. In some experiments volunteers were exposed to sunshine (80-140 min) or the shin region was illuminated (80-95 min) by a commercial UV-A lamp (400 W at a distance of 50 cm). In control experiments ACh release between 20 and 80 min (B1) amounted to 118+/-32 pmol (n=17) and gradually declined between 80 and 140 min (B2) to 112+/-34 pmol, resulting in a B2/B1 ratio of 0.95. When the skin was exposed to sunlight ACh release increased from 205+/-58 pmol (B1) to 349+/-122 pmol resulting in a B2/B1 ratio of 1.70. UV-A radiation, however, had no significant effect on the B2/B1 ratio. When very smooth tactile stimuli were applied by a cotton wool tip for 20 min to the skin close to the microdialysis membranes in a dark room, ACh release was increased from 9+/-2 pmol/20 min to 52+/-36 (n=7). In conclusion, the in vivo release of ACh from the human skin appears to be regulated by external stimuli like sunlight and tactile stimuli.     

8-METHOXYPSORALEN-A Short Review and Comment

8-Methoxypsoralen is a purified extract of the root ammi majus lynn, which was used in a crude form for centuries in the Middle East in the treatment of various skin diseases. In recent years it has been found that the purified extract, when taken internally, increases all skin responses to sunlight, including tanning. When too much drug is taken or when the patient is exposed to sunlight too long, the preliminary erythema may be painful, and blistering may occur. In some patients with vitiligo, islands of pigmentation appear around the hair follicles when the drug is taken, and in favorable cases these islands may coalesce to form continuous areas of pigmented skin. The drug has been found nontoxic, but successful treatment of vitiligo takes place in only a small proportion of patients. Promiscuous use of the drug for cosmetic tanning is to be deplored. The constant irritation of the skin due to the increased action of sunlight when the drug is used may possibly increase the incidence of sun-induced skin cancers.A topical preparation is available, which, when used with great care, may help to repigment small areas of vitiligo.     

Wealth, inequality, and insolation effects across the 19th century white US stature distribution

Sources associated with 19th century stature variation have been widely considered. Using US state prison records and robust statistics, this paper illustrates that 19th century US white statures were positively associated with a broad combination of wealth, equality, and environmental characteristics. Individuals from geographic areas characterized by low wealth and high inequality had shorter statures. After controlling for various factors, direct sunlight – the primary source of vitamin D – was also positively associated with stature. After controlling for wealth, inequality, and insolation, farmers were taller than workers in other occupations. These wealth, insolation, and socioeconomic relationships are significant across the stature distribution.     

Cytogenetic effects in workers occupationally exposed to tobacco dust

Tobacco dust mainly contains nitrosamines, which are readily absorbed by the body tissues like skin, respiratory epithelium, and mucous membrane of mouth, nose and intestines. Exposure to tobacco dust is known to affect the respiratory tracts in humans. In the present study, cytogenetic effects of exposure to tobacco dust are evaluated in 154 male tobacco factory workers and 138 age and sex matched controls by analysing chromosomal aberrations in their peripheral blood lymphocytes. The workers were in the age group of 20-55 years and were employed in the tobacco processing factory for 1-32 years. Heparinised blood samples were collected from workers and control subjects and lymphocyte cultures were carried out by using standard technique. Slides were prepared and 150 metaphases were screened for each sample for various structural and numerical types of abnormalities. A statistically significant increase was observed in the frequencies of chromosomal aberrations in non-smoking and smoking exposed groups when compared to the respective controls. An increase in the frequencies of chromosomal aberrations was also observed with increase in years of service in the exposed subjects.     

8-METHOXYPSORALEN—A Short Review and Comment

8-Methoxypsoralen is a purified extract of the root ammi majus lynn, which was used in a crude form for centuries in the Middle East in the treatment of various skin diseases. In recent years it has been found that the purified extract, when taken internally, increases all skin responses to sunlight, including tanning. When too much drug is taken or when the patient is exposed to sunlight too long, the preliminary erythema may be painful, and blistering may occur. In some patients with vitiligo, islands of pigmentation appear around the hair follicles when the drug is taken, and in favorable cases these islands may coalesce to form continuous areas of pigmented skin. The drug has been found nontoxic, but successful treatment of vitiligo takes place in only a small proportion of patients.Promiscuous use of the drug for cosmetic tanning is to be deplored. The constant irritation of the skin due to the increased action of sunlight when the drug is used may possibly increase the incidence of sun-induced skin cancers.A topical preparation is available, which, when used with great care, may help to repigment small areas of vitiligo.     

Occupational exposure and respiratory health of workers at small scale industries

Certain occupations like welding, painting, and vehicle repairing are associated with regular exposure to dust, exhausts, fuels, fumes, PM, and vapors of welding, solvents, and paint. Many studies have proved a reduction in lung functions due to exposure to these agents. The present study aims to assess and compare respiratory symptoms and pulmonary functions among exposed and non-exposed persons as well as suggests controls respectively. A cross-sectional case study was carried out among small scale industry workers having matched demographic and anthropometric parameters. Medical Research Council (MRC) questionnaire and Micro Direct computerized automated spirometer were used for recording respiratory ailments and pulmonary function tests (PFT) respectively. The percentages of mechanics, welders and painters were 40.9, 31.8, and 27.3 respectively. The highest reported respiratory symptom was chest tightness and whistling among exposed (22.7%) and unexposed (10%). Among study exposed cases, the occupational exposure was found as often (22.7%), sometimes (68.2%) and never (9.1%) while the reported use of airway protection (masks) was very low. Overall respiratory health of the exposed versus controls was reported as excellent (54.5% vs 73.4%), good (27.3% vs 23.3%) and average (18.2% vs 3.3%) respectively. The exposed group on contrary to control one has decreased mean values for FEV1 (3.12 vs 3.50), FVC (4.12 vs 4.43), FEV1/ FVC % (79.60 vs 80.79) and PEF (414.77 vs 523.16). The present study reveals that exposed workers are at increased risk of developing respiratory symptoms and decreased pulmonary functions as compared to unexposed. Such exposure research studies are instrumental in health status evaluation of workers. However, this area has been neglected by the researchers in Saudi Arabia. It is, thus, strongly recommended to carry out prospective studies to substantiate the study results including large sample size, background pollutants concentrations and biological monitoring. Control strategies should be adopted to reduce the vapor concentration in the ambient air, protect and promote respiratory health of workers.     

Osteopontin expression in normal skin and non-melanoma skin tumors.

Osteopontin (OPN) is an adhesive, matricellular glycoprotein, whose expression is elevated in many types of cancer and has been shown to facilitate tumorigenesis in vivo. To understand the role of OPN in human skin cancer, this study is designed to determine whether OPN is expressed in premalignant [solar/actinic keratosis (AK)] and in malignant skin lesions such as squamous cell carcinomas (SCC) and basal cell carcinomas (BCC), as well as in normal skin exposed or not exposed to sunlight. Immunohistochemical analyses showed that OPN is expressed in SCC (20/20 cases) and in AK (16/16 cases), which are precursors to SCC, but is absent or minimally expressed in solid BCC (17 cases). However, positive staining for OPN was observed in those BCC that manifest differentiation toward epidermal appendages such as keratotic BCC. In sunlight-exposed normal skin, OPN is minimally expressed in the basal cell layer, but in contrast to those not exposed to sunlight, OPN is more prominent in the spinous cell layer with increasing intensity toward the granular cell layer. Additionally, OPN is expressed in the hair follicles, sebaceous glands, and sweat glands of normal skin. In conclusion, these data suggest that OPN is associated with keratinocyte differentiation and that it is expressed in AK and SCC, which have metastatic potential, but minimally expressed in solid BCC.     

DNA-protein crosslinks as a biomarker of exposure to solar radiation: a preliminary study in brick-kiln workers.

In India, fired clay bricks are produced in small-scale factories. There are 60, 000 active brick kilns, providing employment to nearly 12 million people in different suboccupations. This industry is largely non-mechanized and operates from November to June. Almost all the workers are exposed to direct sunlight for 8-10 h a day. Cellular DNA-protein crosslinks (DPCs) are the biologically active nucleoprotein complexes formed between DNA and proteins. Ultraviolet light and gamma-rays, and other suspected carcinogens in humans, induce DPC formation in blood cells. DPCs have therefore been identified as a biomarker for monitoring exposure to these hazardous agents. Here we report steady-state levels of DPCs in human peripheral lymphocytes from 46 brick-kiln workers exposed occupationally for 8-10 h a day to solar radiation in brickfields and 25 unexposed controls. A significant increase (p <0.05) in DPC content and DPC coefficients in peripheral lymphocytes was observed in the brick-kiln workers compared with the controls. The data suggest that the DPC content of lymphocytes could be a possible biomarker of exposure to solar radiation. However, further work is necessary to confirm this.     

Unsuspected exposure to asbestos and bronchogenic carcinoma.

Two hundred and fifty men admitted to a thoracic surgical centre and matched controls were questioned in detail about their occupations after leaving school and their smoking habits. Of 201 men with confirmed bronchial carcinoma 58 gave a history of occupational exposure to asbestos, whereas only 29 out of 201 men matched for age and residential area who were admitted with other diseases gave such a history. This difference was statistically highly significant. The usual association of bronchial carcinoma with heavy smoking was observed, but asbestos exposure increased the risk of carcinoma whatever the level of smoking. These results are consistent with the hypothesis that asbestos exposure and the level of smoking act independently in causing bronchial carcinoma. The patients with carcinoma who had been exposed to asbestos presented on average three years earlier than those who had not been exposed. Asbestos regulations have eliminated the risk of exposure to workers in scheduled industries, so asbestos-induced diseases will probably be increasingly found among the many workers who have had incidental exposure to asbestos. It is therefore important to take a full occupational history.     

Long-term health risk to the skin of ultraviolet radiation

The major well-proven long-term health risks of excessive exposure to ultraviolet (UV) radiation relate to the skin. Premalignant skin lesions are seen very much earlier in white skinned populations exposed to excessive sunlight, and over time these same individuals develop larger numbers of all of the three major skin cancers than individuals who do not experience excessive UV exposure. These three skin cancers are squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and malignant melanoma. In the case of SCC the major aetiological pattern is chronic long-term exposure, but for BCCs the pattern appears to be slightly different with short-term burning episodes being more important. In the case of melanomas, there is evidence that for the 4 main types of melanomas, the pattern of excess UV exposure which is most injurious varies.     

Potential protection of skin by acute UVA irradiation--from cellular to animal models

The UVA (320-380 nm) component of sunlight has oxidizing properties which may be deleterious to skin cells and tissue but can also lead to the strong up-regulation of the heme-catabolizing enzyme, heme oxygenase-1. This enzyme has well-established antioxidant actions in cells as well as anti-inflammatory properties in mammals. There is also evidence from rodent models that this enzyme is responsible for the UVA-mediated protection against UVB-induced immunosuppression that occurs in skin. The relevance of these findings to acute and chronic effects of sunlight including skin carcinogenesis is currently under investigation as are the potential implications for sunlight protection in humans.     

Ecological factors in skin color variation among Papua New Guineans

An EEL reflectance spectrophotometer was used to measure the skin color of the inner upper arm and the forearm of 913 Karkar Islanders (Madang District) and 684 Lufa villagers (Eastern Highlands District). The samples were subdivided to study sex, age, and population variation against a background of ecological observations, including sunlight exposure, clothing, and erythemally effective wavelengths of ultraviolet light (Robertson, unpublished Ph.D. thesis, 1974). Population differences in sex and age variation in upper arm skin color may largely be attributable to the effects of culturally associated clothing differences. Not only do the Lufa villagers wear substantially less clothing than the Karkars, but also their arms are exposed more frequently to ultraviolet light during heavy manual work in unshaded gardens. For the melanin content of the forearm skin there are similar patterns of age variation in both populations; however, the populations differ in mean percentage of reflectance throughout most of the age span. These between-population differences are interpreted as a consequence of greater average daily exposure to sunlight and the higher intensity of ultraviolet light in the highland environment. On the forearm the percentage of reflectance at 685 nm decreases more rapidly with age in the prepubertal and adult age groups, a result attributed to endocrine changes superimposed on cumulative changes in the melanin pigmentary mechanism.     

Are there mechanistic differences between ultraviolet and visible radiation induced skin pigmentation?

Most of the studies on sunlight-induced pigmentation of skin are mainly focused on ultraviolet (UV) radiation-induced pigmentation and ways to prevent it. Recent studies have shown that the visible component of sunlight can also cause significant skin pigmentation. In the current study, the extent of pigmentation induced by UV and visible regions of sunlight in subjects with Fitzpatrick skin type IV-V was measured and compared with pigmentation induced by total sunlight. The immediate pigment darkening (IPD) induced by the visible fraction of sunlight is not significantly different from that induced by the UV fraction. However, the persistent pigment darkening (PPD) induced by visible fraction of sunlight in significantly lower than that induced by the UV fraction. The dose responses of IPD induced by UV, visible light and total sunlight suggest that both UV and visible light interact with the same precursor although UV is 25 times more efficient in inducing pigmentation per J cm(-2) of irradiation compared to visible radiation. The measured diffused reflection spectra and decay kinetics of UV and visible radiation-induced pigmentation are very similar, indicating that the nature of the transient and persistent species involved in both the processes are also likely to be same.     

Heat Shock Protein 27 is overexpressed in the skin of bitumen exposed workers. Early observations

The skin of road pavers is exposed to a large number of compounds such as asphalt, bitumen, amines, polymers, oils, solvents, sand, gravel, crushed rock, mineral wad, ultraviolet light and heat. In order to verify an up-regulation of HSP27, determined by the above mentioned stimuli, we studied, immunohistochemically, the forearm skin of a sample of road pavers occupationally exposed. A total of 25 punch biopsies (3 mm diameters) was obtained from the foream skin of road paver workers (n=16) and a control group (n=5) not exposed. Specimens were sectioned (thickness: 3-4 micron ) and processed for immunohistochemistry. For localization of HSP27, a mouse anti-HSP27 monoclonal antibody was used. In punch biopsies of bitumen exposed workers, HSP27 immunostaining was hemogeneously detected in the whole epidermis including basal cell layer. Immunoreaction products were observed mostly in cytoplasm but also in nuclei. Staining intensity was stronger (grade 3 or 4) than that revealed in normal skin sample.     

Stressed out mitochondria: The role of mitochondria in ageing and cancer focussing on strategies and opportunities in human skin

Mitochondrial DNA damage has been used as a successful and unique biomarker of tissue stress. A valuable example of this is sun damage in human skin which leads to ageing and skin cancer. The skin is constantly exposed to the harmful effects of sunlight, such as ultraviolet radiation, which causes it to age with observable characteristic features as well as clinical precancerous lesions and skin cancer. Formation of free radicals by the sun's harmful rays which contribute to oxidative stress has been linked to the induction of deletions and mutations in the mitochondrial DNA. These markers of mitochondrial DNA damage have been proposed to contribute to the mechanisms of ageing in many tissues including skin and are associated with many diseases including cancer. In this article we highlight the role of this important organelle in ageing and cancer with particular emphasis on experimental strategies in the skin.     

Piebaldism in tree shrews

Two types of hair changes occurred in an experimental group of captive tree shrews (Tupaia glis) living on an artificial diet in dark laboratory quarters. The most common variation in the fur consisted of a gradual type of hair loss resulting in a sparse coat and dry skin. The second type of hair change occurred in a female tree shrew in which patches of hair fell out all over the body. White hair regrowth followed exposure to sunlight, with subsequent repigmentation of the bases of the new hairs. Tree shrews suffering from the first type of hair disorder also improved when exposed to sunlight.     

Are healthcare workers in England and Wales at increased risk of tuberculosis?

OBJECTIVE: To determine whether healthcare workers in England and Wales are at increased risk of tuberculosis and to examine the frequency of drug resistance in this population. DESIGN: Comparison of notification rates by occupation obtained from national tuberculosis notification surveys in 1988 and 1993, with denominators from the 1991 census. SUBJECTS: People with notified tuberculosis in professional and associate professional occupations from the two surveys. MAIN OUTCOME MEASURES: Rates of notified tuberculosis in health professionals (mainly doctors) and health associate professionals (mainly nurses) compared with rates in other professional and associate professional occupations, adjusted for ethnic group, sex, and age. RESULTS: 119 cases of tuberculosis were identified in healthcare workers, including 61 nurses and 42 doctors. The crude notification rate in healthcare workers was 11.8 per 100,000 per year (95% confidence interval 9.8 to 14.1) compared with 3.3 per 100,000 per year (2.9 to 3.6) in other professional and associate professional occupations; rate ratios were higher (range 1.7 to 3.2) in all ethnic groups. The relative risk adjusted for ethnic group, sex, and age was 2.4 (95% confidence interval 2.0 to 3.0), slightly higher for health professionals (2.7 (1.9 to 3.8)) than for associate professionals (2.0 (1.5 to 2.6)). No multiple drug resistant strains of tuberculosis were identified in healthcare workers. CONCLUSIONS: Better detection and notification of cases of tuberculosis in healthcare workers may account for some of the apparent increased risk, but these findings imply that tuberculosis remains a hazard for healthcare workers and highlight the importance of ensuring that occupational health monitoring and protection workers are not neglected.     

Incidence of non-melanocytic skin cancer treated in Australia

In 1985, as part of a national random household omnibus survey by a market research company, 30 976 Australians (mostly of European origin) were asked whether they had ever been treated by a doctor for skin cancer. The treating doctor or hospital was then approached for confirmation of the diagnosis of all those people who claimed to have been so treated within the past 12 months. Demographic data were also collected, permitting analysis by age, sex, country of birth, current residence, and skin reaction to strong sunlight.Melanomas accounted for less than 5% of the tumours treated. The world standardised incidence of melanoma was 19/100 000 population. The standardised incidence of treated non-melanocytic skin cancer in Australia was estimated to be 823/100 000. The standardised rates for basal cell carcinoma and squamous cell carcinoma were 657 and 166/100 000 respectively, yielding a standardised rate ratio of about 4:1. Standardised rates based on medically confirmed cases only were 555, 443, and 112/100 000 for all non-melanocytic skin cancers, basal cell carcinomas, and squamous cell carcinomas respectively.Significant differences and trends in incidence were noted with respect to age and sex. Rates in men were higher than those in women but significantly so only after the age of 60. People born in Australia had a rate of 936/100 000 compared with 402/100 000 in British migrants. Rates for non-melanocytic skin cancer showed a gradient with respect to latitude within Australia. The rate in people residing north of 29°S was 1242/100 000 compared with a rate of 489/100 000 in those living south of 37°S. A person''s skin reaction to strong sunlight was a good indicator of the risk of skin cancer, tanning ability being inversely related to its incidence. The rate in those who always burnt and never tanned when exposed to strong sunlight was 1764/100 000 compared with a rate of 616/100 000 in those who always tanned and never burnt.These findings have important implications for public education programmes in relation to exposure to sunlight in Australia.