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Biomedical subjects

J R Nethercott

Publications and source records attributed to J R Nethercott.

At least 37 records · Page 2Linked to original sources

Cutaneous nickel sensitivity in Toronto, Canada.

Patch tests were administered to 1074 subjects with suspected contact dermatitis by the method recommended by the International Contact Dermatitis Research Group. Of 629 subjects tested with 5% nickel sulfate in petrolatum, 10.5% had positive reactions (males, 5.1%; females, 16.7%). Of 447 subjects tested with 2.5% nickel sulfate in petrolatum, 11.9% reacted (males, 7.7%; females, 16.9%). In 447 subjects in whom the relationship between clinical findings and the patch test response was evaluated (i.e., relevance), more than 90% of the responses could be related to a past or present problem with contact dermatitis. The sites of involvement were not different between nickel-sensitive subjects and the overall population tested, except in the case of foot involvement, which was underrepresented in the nickel-sensitive group. Patients who had positive responses to nickel reacted more frequently to marginal irritants such as formaldehyde and benzoyl peroxide. This finding may suggest a reduction in the irritancy threshold in nickel-sensitive subjects. In most instances, domestic rather than occupational exposure was thought to account for the induction of nickel allergy.

Canada↗

Dermatitis in hairdressers.

Occupational contact dermatitis in hairdressers is a common clinical dermatologic problem. Apparently often secondary to irritant contact dermatitis caused by shampooing in Europe, in North America, allergic contact dermatitis related to the chemicals handled, especially oxidation dyes and permanent waving components, is not infrequently the problem. The preponderance of women in the clinical populations reported may well explain the relation noted between a positive patch-test response to nickel and the presence of contact dermatitis in hairdressers rather than nickel allergy predisposing to the disease. There is at present no convincing evidence for excluding persons with a medical or family history of atopy with the proviso that those with a history of hand eczema or atopic dermatitis would be wise to avoid the trade. Improved worker education about the cutaneous risks of the occupation and appropriate simple cutaneous industrial hygiene measures may offer some hope of modifying the risk of developing skin disease.

Adolescent↗

A review of 79 cases of eyelid dermatitis.

Seventy-nine patients with eyelid dermatitis and 1012 patients with dermatitis at other sites were assessed with patch tests. Eighty-nine percent of the eyelid cases involved women. Only the eyelids were involved in 78.5% of cases. Of the patients with eyelid dermatitis 46% had allergic contact dermatitis, 15% had irritant contact dermatitis, and 23% had atopic dermatitis. Only 13% were work related. Positive reactions to patch tests for cinnamic alcohol, diazolidinyl urea, and neomycin sulfate occurred more frequently, whereas those for cobalt and nickel occurred less frequently, in patients who had eyelid dermatitis when compared to the reactions of patients who did not have eyelid dermatitis.

Adult↗

Occupational dermatitis in food handlers and bakers.

Of 1346 patients with suspected contact dermatitis examined in Toronto, 10 bakers and 10 food handlers were found to have occupational contact dermatitis. Although not dissimilar in age, years in the trade, or length of illness, men were significantly overrepresented in the population of bakers (100% vs 40%, p less than 0.05). One baker had occupational asthma related to rye flour. Compared with the bakers, significantly more of the food handlers had allergic contact dermatitis (70% vs 20%, p less than 0.05). In addition to food components, cinnamates and rubber were found to be causes of allergic response. One food handler had contact urticaria caused by shellfish. The standard screening tests, combined with the use of contactants specific to occupational history, yielded a definitive determination of the existence of a contact allergy in our subjects.

Adult↗

Acute and chronic respiratory effects of occupational exposure to ammonia.

In a soda ash plant, 58 workers exposed to mean airborne ammonia levels of 9.2 +/- 1.4 ppm were compared with 31 control workers with a mean exposure of 0.3 +/- 0.1 ppm. There were no differences between the groups in the reporting of respiratory or cutaneous symptoms, sense of smell, baseline lung function, or change in lung function over a work shift at the beginning and end of a workweek. No relationships between level or length of ammonia exposure and lung function results were demonstrated.

Acute Disease↗

Occupational contact dermatitis due to epoxy resin in a fiberglass binder.

Eight workers handling fiberglass coated with uncured epoxy resin, out of a population of approximately 130 workers, developed dermatitis of their hands and forearms. Four also had involvement of the head and neck. Epicutaneous testing established the presence of contact allergy to epoxy resin in six, and one worker had continuous sensitivity to cresylglycidyl ether. Workers handling the coated material after it had been heat-cured were not affected, even if they had had problems with dermatitis while handling the uncured coated fiber.

Adult↗

Comparison of health of occupants and characteristics of houses among control homes and homes insulated with urea formaldehyde foam. I. Methodology.

The methodology of a study in which a comparison is made of the health and house characteristics of the occupants of 231 control homes and 571 houses containing urea formaldehyde foam insulation (UFFI) is described. All homes and occupants were examined on two occasions separated by an interval of 12 months, during which two-thirds of the UFFI houses performed remedial work. The occupants were examined using a health questionnaire and a series of objective tests including pulmonary function, nasal airway resistance, sense of smell, nasal surface cytology, and patch tests. The houses were assessed using a questionnaire and measurements of indoor formaldehyde and carbon dioxide levels. No obvious bias has been identified in this survey with respect to the representativeness of the population studied, the classification of the UFFI and control groups, and the input from both the respondents and observers. The symptom responses made by individuals within the same households were not correlated. Quality control assessment of the objective health tests and formaldehyde sampling and assays demonstrated that these procedures remained stable over the two phases of the study, with the exception of the expected decrease in the pulmonary flow rates over 1 year and a small unexpected increase in the forced vital capacity and the forced expiratory volume in 1 s.

Airway Resistance↗

Comparison of health of occupants and characteristics of houses among control homes and homes insulated with urea formaldehyde foam. II. Initial health and house variables and exposure-response relationships.

A health survey was conducted on 1726 occupants of urea formaldehyde foam insulated (UFFI) houses and 720 residents of control homes. The occupants of the UFFI houses showed a modest excess of many symptoms relative to the controls. This excess of complaints was contributed mainly by the residents of households which were intending to have their UFFI removed and by onsets which followed the installation of UFFI. There were no associated abnormalities in nasal airway resistance, sense of smell, pulmonary function, or patch tests for allergy to formaldehyde. However, the UFFI subjects intending to have their UFFI removed demonstrated a small increase in nasal epithelial squamous metaplasia. The indoor formaldehyde levels of the UFFI houses were about 20% higher than in the controls, while the carbon dioxide levels were similar in both groups. The UFFI subjects showed positive relationships between level of formaldehyde exposure and the presence of a number of symptoms, which were largely dependent on a small group of formaldehyde values that were in excess of 0.12 ppm. A number of the exposure-response relationships were enhanced by UFFI. These results suggested that some adverse health effects of UFFI were explained by formaldehyde alone while others were related to the combined effects of formaldehyde and an additional UFFI-related factor(s) which was not identified.

Carbon Dioxide↗

Health status of a group of sewage treatment workers in Toronto, Canada.

Fifty randomly selected workers in a sewage treatment plant using a heat treatment method for processing sewage sludge in Toronto, Canada were assessed. This investigation revealed that many workers reported "influenza-like" symptoms, cough, sputum production, wheezing, sore throat and skin complaints. The workers tended to have somewhat reduced lung function. Workers in the area of the plant where boiled sewage sludge was dried frequently reported an intermittent, acute illness characterized by cough, fever and sore throat. Workers in the area of the plant where the dried sludge was incinerated tended to have reduced lung function. The basis for the possible health effects demonstrated has not been established, and further investigation is suggested. The mean level of polychlorinated biphenyls (PCBs) detected in the workers' serum was 6 +/- 5 ppb. The PCB levels could not be related to symptoms or clinical findings in the workers studied.

Acute Disease↗

Occupational contact dermatitis due to glutaraldehyde in health care workers.

Allergic contact dermatitis to glutaraldehyde was found in 13 health-care workers with hand dermatitis. Concomitant sensitivity to other chemicals was noted in 10. The positive patch test response was only evident for every 2nd observation in 4. The eruption persisted for more than 6 months in 10 subjects. In 5, the skin disease forced the worker to leave his occupation.

Adult↗

Contact dermatitis in funeral service workers.

84 funeral service workers and 38 control workers were evaluated for the presence of skin disease by history, clinical examination and patch tests with formaldehyde and glutaraldehyde. No relationship between either personal or family history of cutaneous or respiratory manifestations of atopy and clinical parameters of cutaneous disease or patch test results was found. Cutaneous disease was reported in apprentices, active embalmers and inactive embalmers in decreasing order of frequency. Positive patch test reactions to formaldehyde and glutaraldehyde were found in 4% and 7% of the exposed workers, but in none of the controls. Although exposure to glutaraldehyde was less frequent, the prevalence of positive patch test reactions did not differ. This may suggest that glutaraldehyde poses a greater practical risk of cutaneous sensitization in this trade than formaldehyde.

Adult↗

Dermatitis in the printing industry.

Dermatitis is not an uncommon occurrence in the printing trades. The risk of irritation or allergy varies with the different types of printing methods. Once established to the point of disabling the worker, the occupational dermatitis tends to persist.

Dermatitis, Contact↗

Respiratory effects and dust exposures in hog confinement farming.

Fifty-three hog confinement farmers and 43 control farmers were studied. Pulmonary function, total and respirable personal dust levels, and responses to a health status questionnaire were obtained for all farmers. The hog farmers' total and respirable personal dust exposures were significantly higher than the respective levels of the control farmers. Higher dust levels were associated with the use of floor (scatter) feeding, indoor feed grinding, and the use of high moisture corn feed. Pork producers reported respiratory symptoms significantly more often than controls. Lung function did not differ between the two groups of farmers, nor could dust exposure levels be related to lung function.

Adult↗

Localized subepidermal bullae after intravenous phenobarbital.

The occurrence of subepidermal bullae and sweat gland necrosis in barbiturate-induced coma is well recognized. We report the case of a patient who received intravenous phenobarbital for refractory seizures and subsequently sustained subepidermal bullae without sweat gland necrosis in the skin around and proximal to the intravenous site. Although this may have been secondary to extravasation, a different mechanism of barbiturate-induced bulla formation may exist.

Aged↗

Wood dust and formaldehyde exposures in the cabinet-making industry.

Time-weighted average (TWA) personal total and respirable dust exposures were determined gravimetrically for 48 subjects in 4 cabinet-making plants. TWA personal formaldehyde exposures also were obtained, with the use of 3M 3750 passive monitors. Selective area sampling for formaldehyde was undertaken using two methods. The results obtained with the passive monitors were compared to the standard chromotropic acid impinger method. Considerable variation was noted in the dust exposures. Cabinet-makers exposed to softwoods were found to have a mean exposure of approximately one half of the current applicable ACGIH TWA-TLV, while hard-wood exposure was twice the applicable TWA-TLV. The highest dust exposures were recorded for those workers sanding, the mean total dust being 2.91 mg/m3 (S.E. 0.70) and respirable dust 0.63 mg/m3 (S.E. 0.20). Sanding operations also were found to produce a higher proportion of respirable dust (22%) than other woodworking operations (6%-14%). Workers in assembly areas also were found to have higher dust exposures, likely reflecting the fact that conventional dust collection devices for stationary woodworking equipment are not appropriate for hand held tools and hand sanding. The importance of making respirable dust measurements is discussed. The poor correlation between paired total and respirable dust concentrations indicates that both measurements should be made. Some potential limitations to respirable wood dust sampling using 10 mm nylon cyclones are noted, however. Area dust concentrations were found to be significantly lower than personal exposures, emphasizing the importance of personal sampling data. Formaldehyde vapor exposures were very low, with a mean of 0.06 ppm (S.E. 0.01).

Air Pollutants, Occupational↗