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Biomedical subjects

D Enarson

Publications and source records attributed to D Enarson.

At least 19 recordsLinked to original sources
PubMed1989

Tuberculosis in British Columbia among immigrants from five Asian countries, 1982-85.

The influence of immigration from six selected Asian countries--Japan, Korea, Philippines, India, China and Hong Kong--on the incidence of tuberculosis in British Columbia has been examined. During the period 1982-1985 the average annual incidence of bacillary tuberculosis in these immigrants was more than six times as great as the overall British Columbia rate and contributed a quarter of the cases of active bacillary tuberculosis in this province whereas the immigrants from these countries represented only 3.7% of the total population. The clinical patterns of active tuberculosis by birthplace were analysed. A high proportion of cases of lymphadenitis was seen among all immigrants from Asia, particularly those from the Philippines. Both primary and secondary drug resistance was substantially higher than in Canadian-born patients. The frequency of primary drug resistance was higher among patients aged less than 40 years than those aged 40 or more.

British Columbia↗
PubMed1986

Trace metals in scalp hair of children and adults in three Alberta Indian villages.

This study examined trace metal levels in scalp hair taken from 122 children and 27 adult residents of three small northern Alberta (Canada) Indian villages, one of which is situated close to the world's first tar sands oil extraction plants. The three communities studied were: Fort McKay (the exposed village), Fort Chipewyan (also in the tar sands ecosystem but distant from the plants), and Garden River (not in the tar sands ecosystem). Inductively coupled argon plasma emission spectroscopy was used to determine hair sample metal content. Nineteen metals were included in data analysis. Children from Fort McKay had the highest average hair lead, cadmium and nickel levels. Chromium levels were approximately equal in hair from Fort McKay and Garden River children, and significantly elevated above levels found in the hair of Fort Chipewyan children. Children from Garden River showed highest hair levels of eight metals: vanadium, aluminum, iron, manganese, barium, zinc, magnesium and calcium. Fort Chipewyan children had the highest hair levels of copper, but the lowest levels of all other metals. Among adults, hair lead, nickel and cadmium levels were highest in Fort McKay residents, while phosphorous and vanadium were highest in hair from Garden River residents. Bioaccumulation of lead, cadmium, nickel and chromium in hair from Fort McKay residents may be related to exposure to extraction plant pollution. Plant stack emissions are known to contain appreciable amounts of lead, nickel and chromium. Spills into the Athabasca River, until recently the source of Fort McKay drinking water, have been reported from plant wastewater holding ponds, known to contain elevated levels of lead, nickel and cadmium. An increased number of significant metal-metal correlations in hair metal levels for Fort McKay children suggests a richer source of multiple metal exposure, relative to children in the other two communities.

Adolescent↗
PubMed1985

Grain dust and respiratory health.

Exposure to grain dust gives rise to many respiratory problems. Since the growing, transporting and processing of grain are major Canadian industries, the number of individuals who might be affected by such exposure is sizeable. This paper describes clinical syndromes related to grain dust exposure, together with predisposing host factors, in an attempt to determine what levels of exposure are "safe" for workers and what areas still require extensive research.

Airway Resistance↗
PubMed1985

Does a family history of allergy predict immediate skin test reactivity?

The value of a family history of allergy in predicting atopy was assessed in men employed in lumber mills, grain handling and railway industries in British Columbia. Detailed family and personal histories of allergy were available for 1434 men, 1426 of whom underwent prick skin testing with two common environmental allergens and one control solution. Those with a family history of allergy had 2.06 times the odds of immediate skin test reactivity as those without a family history and 1.65 (p less than 0.01) times the odds after adjustment for personal history and age. The odds of skin test reactivity in workers with a personal history of allergy were 4.76 times those of workers without such a history and 4.34 after adjustment for family history and age. Almost half (47%) of the workers with both a family and a personal history of allergy had positive results of skin testing, compared with only 10% of the workers without either history. It was therefore concluded that a family history of allergy is an independent predictor of atopy.

Adolescent↗
PubMed1985

Respiratory abnormalities among workers in an iron and steel foundry.

A study of the health of 78 workers in an iron and steel foundry in Vancouver, British Columbia, was carried out and the results compared with those found in 372 railway repair yard workers who were not significantly exposed to air contaminants at work. The foundry workers were exposed to PepSet, which consists of diphenyl methane diisocyanate (MDI) and phenol formaldehyde and their decomposition products as well as to silica containing particulates. A questionnaire was administered by trained interviewers, and chest radiography, allergy skin tests, pulmonary function tests, and methacholine inhalation tests were carried out as well as measurement levels of dust and MDI. Compared with the controls, the foundry workers had more respiratory symptoms and a significantly lower mean FEV1 and FEF25-75% after adjustments had been made for differences in age, height, and smoking habit. Three workers (4.8%) had radiographic evidence of pneumoconiosis and 12 (18.2%) had asthma defined as presence of bronchial hyperreactivity, cough, and additional respiratory symptoms such as wheeze, chest tightness, or breathlessness. Sensitisation to MDI is probably the cause of asthma in these workers.

Adult↗
PubMed1985

Lymphocyte subpopulations in allergic granulomatosis and angiitis (Churg-Strauss syndrome).

We report a case of allergic granulomatosis and angiitis (Churg-Strauss syndrome) in which immunologic parameters, including lymphocyte subpopulations, were determined in the acute phase of the disease and during remission. Hyperimmunoglobulinemia E and immune complexes were present. A low proportion of suppressor/cytotoxic (T8+) lymphocytes and a high helper/suppressor ratio were seen throughout the course of the disease, although immunoglobulin levels and circulating immune complex levels decreased with therapy. We hypothesize that the deficiency of suppressor cells may play a role in the pathogenesis of this syndrome.

Aged↗
PubMed1984

Lymphocyte subpopulations in patients with allergic rhinitis.

The lymphocyte subpopulations were classified using monoclonal antibodies specific for B lymphocytes (B1 antibodies), T lymphocytes (T11 and OKT3 antibodies), helper/inducer T cells (T4 antibodies) and suppressor/cytotoxic T cells (T8 antibodies). Three groups of subjects were studied: 20 normal controls, 29 patients with allergic rhinitis and a subgroup of nine patients who had received immunotherapy. The proportion of B lymphocytes, total T cells and T4 positive (helper/inducer) cells were not significantly different between the groups, but allergic patients were found to have a decreased proportion of suppressor T8 positive (suppressor/cytotoxic) cells and hence a high helper/suppressor cell ratio. These abnormal parameters were found to be normal in the group of allergic patients who had received immunotherapy. These results imply that a suppressor cell deficiency may be an underlying mechanism of allergic disease, and that immunotherapy could correct the suppressor cell deficiency.

Adult↗
PubMed1984

Symptoms, pulmonary function, and bronchial hyperreactivity in western red cedar workers compared with those in office workers.

An epidemiologic health study was carried out on 652 cedar mill workers and a control group of 440 male office workers not exposed to air contaminants. Participants completed a medical-occupational questionnaire with trained interviewers, had allergy skin tests, performed spirometry, and had bronchial reactivity assessed by methacholine inhalation testing. After adjusting for differences in age, race, and smoking, cedar workers were found to have significantly higher prevalences of cough, phlegm, and dyspnea than did office workers. Symptoms of asthma and work-related asthma, but not persistent wheeze or doctor-diagnosed asthma, were reported in a significantly higher proportion of cedar workers than of office workers. Cedar workers also had significantly lower lung function test results than did office workers after controlling for height, age, race, and smoking. Bronchial hyperreactivity, defined by a methacholine PC20 less than 8 mg/ml, was more prevalent among cedar workers than among office workers, with the increase being limited to the nonatopic subgroup of workers. The prevalence of bronchial hyperreactivity increased with duration of employment among cedar workers but not among office workers. We conclude that exposure to western red cedar dust is harmful to the respiratory health of the workers, causing asthma and other respiratory symptoms, bronchial hyperreactivity, and lower levels of lung function.

Adult↗
PubMed1984

Host factors affecting longitudinal decline in lung spirometry among grain elevator workers.

The host factors affecting the longitudinal decline in lung function among 267 white male grain elevator workers who were still working in the industry and did not change their smoking habits over a period of six years were studied. Spirometric measures declined more rapidly in older grain handlers as compared with younger workers. Smokers had slightly greater decline in spirometry compared to nonsmokers, but the differences failed to reach the level of statistical significance. Acute changes in lung function over the course of one work week during the initial study were also positively correlated with subsequent decline in lung function, as was bronchial hyperreactivity determined during the follow-up study. Positive immediate skin reactivity to common allergens, presence and absence of respiratory symptoms, and initial lung function did not appear to influence the subsequent decline in lung function in this group.

Adult↗
PubMed1983

Epidemiologic health study of workers in an aluminum smelter in British Columbia. Effects on the respiratory system.

A health survey was carried out on all white males in an aluminum smelter in British Columbia. The survey consisted of a medical-occupational questionnaire, spirometry, chest radiography, and environmental monitoring. We have compared the results of a respiratory survey in 713 workers in the office and casting department with no significant exposure to air contaminants (control workers) with those of 797 potroom workers: 495 who spent more than 50% of their working time in the potroom (high exposure) and 302 workers who spent less than 50% of their working time in the potroom (medium exposure). Potroom workers (high) had a significantly greater prevalence of cough and wheeze than did those in the control group, and they had significantly lower mean forced expiratory volume in one second and maximal midexpiratory flow rate than did those in the control group after adjustment had been made for differences in age, height, and smoking habits. Potroom workers (medium) had a slightly greater prevalence of respiratory symptoms and lower lung function than did workers in the control group, but the differences were not significant. We were unable to demonstrate potroom asthma. The levels of total fluoride, gaseous fluoride, particulate fluoride, sulphur dioxide, and total particulates found in the potroom at the time of the study were below the currently accepted threshold limit values, but the levels of benzo-alpha-pyrene were high.

Adult↗
PubMed1979

Tuberculosis in immigrants to Canada. A study of present-day patterns in relation to immigration trends and birthplace.

The influences of immigration on tuberculosis morbidity in Canada were examined. The pattern of immigration has changed markedly in recent years, increasing proportions of immigrants being from areas other than Europe. Morbidity rates varied widely according to country of birth and were highest among persons born in Asia and lowest among those born in northwestern Europe and the United States. These rates were generally parallel to those reported in the countries of birth, although somewhat lower. Differences in patterns of disease by birthplace were noted, particularly the preponderance of lymphadenitis in Asians and genitourinary tuberculosis in Italians. Although the frequency of drug-resistant bacilli was higher in Asians than in other groups, the vast majority of bacilli in all groups were drug-sensitive. For purposes of tuberculosis control, immigrants from high-incidence countries constitute a high-risk group, and physicians should be aware of this when dealing with patients from these countries.

Asia↗
PubMedDate not supplied

Epidemiologic health study of workers in an aluminum smelter in Kitimat, B.C. II. Effects on musculoskeletal and other systems.

A health study was carried out on 2066 workers in an aluminum smelter in Kitimat, British Columbia to study the effects of exposure to fluoride and other air contaminants encountered on the potlines on the musculoskeletal system, hemopoietic tissue, liver, and renal function. Three hundred seventy-two railway repair workers from Squamish, British Columbia served as an "external" control group. Examination of the spine and sacroiliac joints and pelvic X-ray were conducted on long-term potline workers and a number of "internal" control workers in the smelter not exposed to any air contaminants. Urinary fluoride measurements and personal sampling for airborne fluoride were also carried out. Blood samples were collected for routine blood count and liver and renal function test. Definite cases of skeletal fluorosis were not found in any potroom workers. Some of the changes of early skeletal fluorosis described on pelvic X-rays, e.g., increased density, calcification of ligaments, and periosteal changes, were found in a few workers who were employed on the potlines for more than 10 yr. There was, however, poor agreement in the findings of the two radiologists who read the films. The entity "musculoskeletal fluorosis" does not exist in this smelter where the potroom workers were exposed to total fluoride levels below the currently accepted threshold limit value of 2.5 mg/m3. No ill effects on the hematopoietic tissue or liver and renal function were found.

Air Pollutants↗