Biomedical subjects

P Pahwa

Publications and source records attributed to P Pahwa.

8 recordsLinked to original sources

PubMed1996

Persistent wheeze in grain elevator workers should not be ignored.

We investigated the relationship between annual change in pulmonary function and changes in respiratory symptoms among male grain elevator workers who participated in a health surveillance program mandated by Labour Canada. The surveillance was conducted every 3 yr starting from the period 1978 to 1981. The 1,211 workers who participated in the second (1981 to 1984) and fifth (1990 to 1993) surveillance were included in the analysis and the mean duration of the follow-up was 8.6 yr. In the analysis we also included the pulmonary function measurements that were available for some subjects at the third and fourth surveillance. The subjects who reported persistent wheeze had the largest mean annual rate change in FEV1 (-44.4 ml/yr) and FVC (-55.3 ml/yr). When adjusted for age, height, weight change, smoking, baseline lung function, location of grain elevators, and duration of employment, the subjects with persistent wheeze had an annual rate change of -28.3 ml/yr (SE 10.5; p = 0.007) in FEV1 and -37.3 ml/yr (SE = 12.3; p = 0.003) in FVC in comparison to subjects without any respiratory symptoms. The subjects who reported new onset of wheeze had significantly greater annual rate changes only in FEV1 (-13.7 ml/yr; SE 6.0; p = 0.02) in comparison to asymptomatic subjects' symptoms. Persistent wheeze is an important predictor of decline in lung function among grain elevator workers and should not be ignored in surveillance programs or clinical evaluations.

Adolescent↗

PubMed1994

Longitudinal estimates of pulmonary function decline in grain workers.

We conducted a cohort analysis of longitudinal changes in pulmonary function test values in male grain elevator workers in five regions of Canada over a 6-yr period involving three observations. Pulmonary function tests were obtained approximately each 3 yr during an observation interval called a "cycle". The periods of the cycles were 1978-81 (Cycle I), 1981-84 (Cycle II), and 1984-87 (Cycle III), respectively. Data on respiratory symptoms and pulmonary function tests were collected on the same 881 workers in Cycles I and II (mean ages +/- SE: 37.0 +/- 0.48 yr at Cycle I), on the same 1,294 workers in Cycles I, II, and III (34.6 +/- 0.34 yr at Cycle I), and on the same 1,021 workers in Cycles II and III (33.9 +/- 0.38 yr at Cycle II) for a total of 3,196 workers with two or more observations over the 6-yr period. The proportion of current smokers decreased from Cycle I to Cycle III. Autoregression analysis of longitudinal changes in lung function data showed that predictors of FEV1 were height, years in the industry, smoking status, and geographic region. The mean annual losses in FEV1 (FVC) were 28.7 ml (26.4 ml), 38.4 ml (41.9 ml), and 41.7 ml (32.3 ml) for nonsmokers, ex-smokers, and current smokers, respectively. The annual loss of FEV1 (FVC) was 9.2 ml (21.1 ml) for those who were in the grain industry for less than 5 yr and 52.6 ml (60.8 ml) for those who were exposed for 20 yr or more.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Prognostic significance of the onset mode in parkinsonism.

Early recognition of the prognosis in parkinsonism is important for both the management and studies aimed at preventing progression of disease. Less favorable prognosis is reported in early-onset postural instability and gait difficulty (PIGD) than in the tremor-onset cases, but the reasons for this are unknown. In 70 autopsy-verified cases, 11 (15.7%) had PIGD, and 34 (49%) had tremor onset. Improvement on levodopa was more common in the tremor-than the PIGD-onset cases (p < 0.05). The majority of tremor-onset cases had Lewy body disease, while the majority of PIGD-onset cases had other forms of pathology. Survival was shorter in the PIGD- than the tremor-onset cases (p < 0.05).

Adult↗

PubMed1992

Clinical evaluation of a light energy conversion toothbrush.

A blind, two-way crossover clinical trial was carried out to compare the effectiveness of plaque removal between a new, light energy conversion toothbrush incorporated with a semiconductor of TiO2 (test) and a similar toothbrush without the semiconductor (control). The study was completed by 73 school children aged 13-15 years. Each toothbrush was used for a period of 3 weeks. The mean differences between baseline plaque scores and after subjects used the test and control brushes were analyzed by the paired t-test. The Soladey 2 toothbrush showed significantly more reduction of plaque on the buccal surfaces of all teeth than the control brush. There was no significant difference in the plaque removing ability of the two brushes on the lingual aspects of the mandible and on the lingual surfaces of the maxillary posterior sextant. As the buccal surfaces are more likely to allow light to reach the semiconductor during brushing than the lingual areas, it is possible that the reported photocatalytic property of the semiconductor may be involved in some way in the observed reduction of plaque.

Adolescent↗

PubMed1992

Decline in spirometric variables in grain workers from start of employment: differential effect of duration of follow up.

Prospective study of 164 young men from the start of employment in grain elevators showed that of those seen at the initial evaluation of respiratory state only 30% were available for a complete four year follow up. The drop out of subjects could represent a health related selection leading to the underestimation of respiratory effects of exposure to grain dust as assessed in the survivor group. This hypothesis was examined by comparisons of longitudinal changes in lung function in four groups defined by the duration of follow up involving the initial examination and periodic evaluations after one, two, and four years of work. Sixty four men were tested only on the initial examination (group I), 18 underwent two (group II), 31 underwent three (group III), and 51 (group IV) all four examinations. The groups had similar mean ages (range: 19.4-20.1 years), mean duration of previous exposure to grain dust (range: 8-13 weeks), smoking habits, lung function, and prevalences of respiratory symptoms evaluated on the initial occasion. The average decline in lung function over the first year was associated with duration of follow up. The annual decline in FVC (ml) was 58 in group II, 41 in group III and -55 (increase) in group IV; the decline in FEV1 (ml) was 224, 130, and 70 respectively. The differences for the annual declines of FEV1, FEF25-759 Vmax509 and Vmax25 were significant between groups II and IV, and the FEF25-759 Vmax509 and Vmax25 differed significantly between groups II and III. The results show that the restriction of analysis to the survivors may underestimate the relation between work and respiratory impairment.

Adolescent↗

PubMed1991

Respiratory health status of 3098 Canadian grain workers studied longitudinally.

Analyses of data on 3098 male individuals surveyed twice by the Labour Canada Medical Surveillance Program for the Grain Industry are presented. The program collects information on respiratory symptoms, job description, and smoking habits of these workers. In addition, each worker performs pulmonary function tests obtainable through spirometry. Chronic sputum production and chronic wheezing were more prevalent during the latest testing period (rising to 17 percent and 13%, respectively), while the prevalence of chronic cough (16%) and dyspnea (10%) did not change significantly. Eighty-two percent of these workers, in each time cycle, had normal pulmonary function despite an additional 3 years of work exposure. In each cycle, obstructive dysfunction (less than or equal to 12% of workers) was more prevalent than restrictive dysfunction (less than or equal to 5%) or combined obstructive/restrictive dysfunction (less than or equal to 2.4%). It is unknown unknown whether this demonstrated dysfunction is due to previous workplace exposure, as Labour Canada and the Canadian grain industry have cooperated in lowering the grain dust levels found in grain elevators and terminals. In addition, the prevalence of current cigarette smoking has declined. (decreases 5%) among these grain handlers, and there is suggestive evidence that those continuing to smoke have reduced their consumption (mean pack-years changed only from 15.3 to 17.4). Knowledge of environmental dangers and educational programs have contributed to these encouraging results.

Adult↗

PubMed1991

Atopic status as a factor in job decision making in grain workers.

We conducted allergy skin-prick testing on 207 young cereal grain workers within 0.27 years of the commencement of their employment in the grain industry and again after 1.34 years of employment on 124 workers. We also studied 120 control subjects on the first observation and 105 on the second observation. Grain workers had lower prevalence than did the controls of positive skin tests on the first observation, and this difference increased by the second observation. Respiratory symptoms were more frequent among grain workers with positive skin tests who dropped out of the industry than among those who stayed in the industry. We conclude that atopic status may be a factor in job selection and drop out decision making and may be a factor explaining the healthy worker effect.

Agricultural Workers' Diseases↗

PubMed1988

Respiratory symptoms and alterations in pulmonary function tests in swine producers in Saskatchewan: results of a survey of farmers.

To determine whether farmers who produced swine in animal confinement chambers in Saskatchewan were at increased risk of developing respiratory dysfunction, we carried out a respiratory health questionnaire and spirometric pulmonary function test measurements, including forced expired volume in 1 second (FEV1), forced vital capacity (FVC), and the ratio of FEV1 to FVC (FEV1/FVC x 100), on 504 farmers who indicated that they raised swine, and 448 rural-dwelling nonfarming control subjects. Swine producers had lower values for FVC and FEV1 than did the control subjects. However, FEV1/FVC x 100 was somewhat higher in the swine producers. The reduction in FEV1 with retained FEV1/FVC ratio is suggestive of restrictive disease. However, the fact that the FEV1/FVC ratio is only modestly higher in swine producers than in control subjects suggests that there may be a mixed restrictive/obstructive condition in these workers.

Adult↗