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Biomedical subjects

T Husain

Publications and source records attributed to T Husain.

35 records · Page 2Linked to original sources
PubMed1991

Psychological responses to thermal stress in a glass bangle factory.

Behavioural studies were conducted on a random sample of 38 glass bangle workers engaged in various occupations and exposed to high ambient temperature (38.2 +/- 3.4 degrees C) and radiant heat (46.2 +/- 5.1 degrees C) during their work in the glass bangle industries at Firozabad, India. Twenty-two control subjects of similar age and socio-economic status unexposed to heat during their work were also studied for comparison. The digit span test, digit symbol test, Bourdon-Wiersma vigilance test, flicker fusion test and Maudsley personality inventory (MPI) were used to assess the behavioural changes induced by the existing heat stress. The mean scores of immediate memory were much lower in the exposed population than in the controls thereby indicating impairment of immediate memory in the study group. The visuo-motor coordination and vigilance were also significantly affected. Visual perception showed a downward trend among the glass bangle workers, although the MPI test indicated no personality changes.

Adolescent↗
PubMed1990

Ventilatory dysfunction in glass bangle workers.

The pulmonary function status of 73 glass bangle workers suffering from chronic bronchitis having varied exposures to pulmonary toxicants in the work environment was evaluated in 1984. The findings were compared with those observed in 220 asymptomatic glass bangle workers and 88 unexposed controls. There was a higher prevalence (45.2%) of ventilatory dysfunction in the chronic bronchitic cases as compared to 19% in the asymptomatic workers and 2.3% in controls, respectively. The relative risk of airway obstruction was 8.3 and 19.6 times higher in the asymptomatic and chronic bronchitic workers respectively as compared to the controls (p less than 0.001). The prevalence of obstructive impairment among the smokers and non-smokers in the exposed workers was not statistically significant. However, age greater than 30 was found to be significantly associated with bronchial obstruction in chronic bronchitic cases. The relative risk of duration of exposure was found to be 1.86 in the asymptomatic workers exposed for more than 10 years (p less than 0.05) while it was 1.62 in workers with chronic bronchitis. The occupational and environmental factors responsible for the high prevalence of chronic bronchitis and associated ventilatory dysfunction in relatively young glass bangle workers are discussed.

Adult↗
PubMed1990

Cardiac stress in glass bangle workers.

The cardiac cost of work and recovery pulse rates were evaluated in 38 glass bangle workers (mean age 27.8 years, SD 3.4) exposed to radiant heat (46.2 degrees C, SD 5.1) and high ambient temperature (38.2 degrees C, SD 3.4) for a mean period of 11.0 years, SD 3.5 in the glass bangle industry. A reference group of 15 controls (mean age 27.0 years, SD 3.5 unexposed to occupational heat stress served as a comparison. The results showed that the pulse rate increased from a mean basal value of 80.0 beats.min-1, SD 2.7 to 113.2 beats.min-1, SD 11.4 in the exposed workers while in the controls the increase was negligible. Thus the cardiac cost of work was found to be 33.2 beats.min-1, SD 11.1 in the exposed group which was significantly higher (P less than 0.001) than 7.8 beats.min-1, SD 4.2 observed in the control group. Among the exposed workers, 'belanias', who were engaged in the strenuous job of manually rotating the iron roller in the Belan furnace so that the molten glass could be wound in a spiral form, showed the maximum increase in the pulse rate (42.0 beats.min-1, SD 7.5) over the work-shift followed by 'muthias' (31.1 beats.min-1, SD 4.0) who were engaged in removing the glass spirals from the Belan furnace. However, wireman ('tarkashs'), who were engaged in the highly skilled job of making very fine threads of molten glass with the help of an iron roller, showed the smallest increase (19.5 beats.min-1, SD 3.4) in pulse rate over the work-shift.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

A global comparison of predicting equations on spirometry in the male population.

A multiple regression model considering dependent variables like vital capacity (VC), forced expiratory volume in one second (FEV1) and peak expiratory flow rate (PEFR) and age and height as independent variables for the adult male population, which includes whites of European descent and non-whites was reviewed to evaluate the role of lung function status following standardization of age and height. Non-whites showed 0.19 litre decline in VC per decade of life as compared to 0.24 litres observed in the whites of European descent. Mean VC increased 0.05 litres per centimetre in non-whites and whites. The variation in the constant term in the regression equation determined the difference between the racial groups. Like VC, FEV1 showed ethnic differences similar to those of VC. However, the magnitude of the variation in the predicted values of FEV1 was found to be less than that observed in VC. When related to VC, FEV1 showed little difference between most European populations, New Guyanaese, Indians, Negroes, Africans and Chinese because FEV1/FVC ratio had a very narrow range between 77 and 80%.

Adult↗
PubMed1990

Pulmonary function study in female grinders exposed to agate dust.

This paper reports a cross-sectional study of a non-smoking population of silica exposed female workers compared with a group of healthy non-exposed females. The exposed group is divided into cohorts according to the presence or absence of pneumoconiosis in either simple or complex form. The study revealed statistically significant difference in pulmonary function between each of the pneumoconiosis group and the controls and healthy exposed workers. Furthermore, there was statistically significant difference between the values of pulmonary function parameters of the healthy exposed group and the controls. The most important observation of the study is that almost equal decrement of pulmonary function values was observed in the diseased groups and in the healthy exposed group compared to the decrement seen between the latter group and the control group. VC and FVC showed a mean fall of 11.0 and 11.5% in the healthy exposed group as compared to those observed in the unexposed controls (p less than 0.01 and p less than 0.05) while in the pneumoconiosis group VC and FVC showed 16.9 and 18.2% decrease as compared with the values obtained in the healthy grinders (p less than 0.01). Similarly FEV1 showed almost same decrease in the healthy (17.9%) and diseased (20.7%) exposed groups (p less than 0.001). However, FEV0.75 and MVV parameters showed greater decrement (25.4 and 33.7%) in the pneumoconiosis group as compared to 15.7 and 18.5% observed in the healthy exposed workers. The important observation made in this study is that potential pulmonary debilitation may occur in pneumoconiosis before, or in the absence of, any radiologic findings.

Adult↗
PubMed1989

Study of respiratory impairment among pesticide sprayers in Mango plantations.

Pulmonary function studies were conducted on 489 pesticide workers engaged in spraying operations on mango plantations. These workers were exposed to a variety of organochlorine and organophosphorus pesticides. A reference group consisting of 208 controls, belonging to the same socioeconomic stratum, was taken from the same area for purposes of comparison. The results of the study showed 36.5 and 41.5% prevalence of respiratory impairment in the exposed workers and in the controls, respectively. The most common pulmonary impairment among the exposed subjects (18.8%) and controls (16.9%) was of the restrictive type, followed by mixed ventilatory defect. Bronchial obstruction affected 2.5 and 3.7% of the exposed and control populations, respectively. In a comparison of the prevalence of total respiratory impairment in the pesticide workers and the controls, the nonsmokers did not show any significant difference in this study. The prevalence rate of respiratory impairment showed an increasing trend in different exposure groups (p less than 0.05), thereby clearly indicating a dose effect. The study revealed that occupational exposure to pesticides had a direct bearing on the respiratory impairment identified in the exposed workers.

Adult↗
PubMed1989

Cardio-respiratory studies on glass bangle workers.

Cardio-respiratory functions were recorded in 18 glass bangle workers (Belanias) who worked near the belan furnace continuously for 2 h. The workers were exposed to high ambient temperature (tDB 38.2 degrees C +/- 3.4 degrees C) and thermal radiation (tG 46.2 degrees C +/- 5.1 degrees C) during their work. The physiological responses recorded after the work spell at 1 (R1) 3 (R3) and 5 (R5) minute intervals exhibited incomplete recovery. The oral temperature remained significantly high (0.74 degrees F +/- 0.27 degrees F) even at R5 and never reached pre-work value. Similarly the heart rate values remained very high (26.4 +/- 5.4 beats/min) at R1, (10.7 +/- 3.9 beats/min) at R3 and (4.01 +/- 2.4 beats/min) at R5 periods during recovery, thereby showing that heart rate did not regain the pre-work status. The incomplete recovery in heart rate revealed cardiac stress in the exposed workers. Besides the cardiac stress, the cardiac cost of the work under the prevailing hot conditions in the glass bangle industry was very high, adding further to circulatory strain in these workers. Almost all the exposed workers were found to have hyperventilation syndrome characterized by increased respiratory frequency and tidal volume resulting in ventilatory stress induced by physical and physiological heat.

Anthropometry↗
PubMed1989

Thermal stress and physiological strain of children exposed to hot environments in a glass bangle factory.

A group of 19 male children (mean age 12.1 years SEM 1.6 years) occupationally exposed to an excessively hot environment for an average duration of 2.5 years SEM 1.7 years in the glass bangle factory in Firozabad, India, were studied to evaluate the physiological strain induced by the thermal radiation (mean radiant temperature 46.2 degrees SEM 5.1 degrees C) and high ambient temperature (38.2 degrees SEM 3.4 degrees C) prevailing in the factory. Over a work-shift the mean increase in oral temperature was 0.90 degrees C in the exposed children, in comparison with the 0.40 degrees C increase recorded in the control children (p less than 0.05). The maximum increase in oral temperature was recorded in 'gulliwalas' (0.90 degrees C) and the minimum in 'battiwalas' (0.80 degrees C). The mean peak value of oral temperature (37.5 degrees C) was observed at 1600 hours. A significant increase in the pulse rate (25.9 beats.min-1) during the work-shift was observed in the exposed children in comparison with a mean increase of 9.4 beats.min-1 in the control group. Ventilatory studies showed pulmonary hyperventilation in the exposed workers. The increase in pulmonary ventilation was in the form of an increase in tidal volume and respiratory frequency induced by high environmental temperatures and thermal radiation. The cardio-respiratory responses showed physiological strain induced by the high ambient temperature and radiant heat prevailing in the glass bangle factory.

Adolescent↗
PubMed1989

A study of the prevalence of ventilatory obstruction in textile workers exposed to cotton dust.

A study was conducted in a cotton spinning mill to assess the prevalence of respiratory impairment in 189 asymptomatic workers and 133 byssinotics drawn from various sections of the plant exposed to airborne cotton dust in the work environment. Eight-four healthy controls belonging to the same socioeconomic status and ethnic group having never been exposed to cotton dust or any other pollutant was also studied for the purpose of comparison. Of the 189 asymptomatic workers, 13 (6.8%) suffered from bronchial obstruction whereas only 2 (2.3%) among the control showed obstructive pulmonary impairment. The byssinotics showed a significantly higher prevalence (15.7%) of bronchial obstruction than that (6.8%) observed among the asymptomatic cotton workers (P less than 0.005). Byssinotics (grade II) showed significantly higher prevalence (31.5%) of bronchial obstruction than that (9.4%) observed in acute byssinotics (grade I). The effect of smoking on the prevalence of bronchial obstruction in the asymptomatic and byssinotics was quite discernible as smokers showed significantly higher prevalence than that observed among the nonsmokers (P less than 0.05). The asymptomatic cotton workers and those with different grades of byssinosis having more than 10 years of exposure showed significantly higher prevalence of bronchial obstruction than that observed in the group with less than 10 years of exposure (P less than 0.005). The healthy cotton workers and byssinotics engaged in the preparatory section (card, blow, and waste plant rooms) showed an insignificant higher prevalence of bronchial obstruction (11.3 and 24.4%, respectively) than among those who worked in the spinning, reeling, and winding sections of the mill. The mechanism responsible for causing ventilatory obstruction in the textile workers is discussed.

Adult↗
PubMed1989

Respiratory health effects from occupational exposure to wood dust in sawmills.

Spirometric lung functions were recorded for 109 workers (mean age 26.4 +/- 8.2 yr) occupationally exposed (mean exposure 8.9 +/- 7.7 yr) to soft wood dust in local sawmills along with 88 unexposed controls (mean age 28.7 +/- 9.9 yr) belonging to the same socioeconomic status to assess the prevalence of respiratory impairment in the exposed population. The results of the study showed a significantly higher prevalence of overall respiratory impairment in the exposed group even after standardizing for smoking habits (p less than 0.001). The adjusted rate for respiratory impairment in the exposed group was 29.4% as compared to 2.2% observed in the unexposed controls. The pattern of respiratory abnormality observed in the sawmill workers was predominantly the restrictive type (28.4%), indicating lower levels of forced vital capacity (FVC) in the exposed group; while in the control group, there were none with lung restriction The prevalence of airflow limitation, however, was similar in the exposed workers (1.8%) and controls (2.2%), thereby, indicating that bronchial obstruction was independent of wood dust exposure. It is concluded that the dust exposure in sawmills is associated mainly with restrictive type of pulmonary impairment in the exposed workers.

Adolescent↗
PubMed1985

The effect of substrate and potassium on the inhibitory kinetics of MnCl2 on the enzyme K+-p-nitrophenyl phosphatase in rat brain.

The effect of Mn2+, a divalent metal, on the enzyme K+-p-nitrophenyl phosphatase (K+-PNPPase) was studied in rat brain. The metal was found to be a moderate inhibitor of the enzyme, with an I50 of approximately 480 microM. The inhibition was pH dependent, but not temperature dependent. On measurement of the inhibition with varying concentrations of PNPP (1-5 mM), the I50 value remained constant. However, when the inhibition was measured with K+ (5-20 mM), the I50 value increased from 130 microM to 490 microM, suggesting that K+ antagonized the effect of Mn2+. In kinetic studies, Mn2+ inhibited the enzyme in a non-competitive manner with respect to PNPP. The Km remained constant (2.9), but the Vmax was decreased from 5.0 to 1.6. However, with respect to K+, the inhibition was competitive, as the concentration for half maximal activation (K0.5) increased from 1.3 to 8.9 mmol l-1 with 1 mM of MnCl2, suggesting that the apparent affinity of K+ for the enzyme was decreased. The apparent Vmax was not affected. The degree of cooperactivity (n) measured as the slope of the Hill plot remained unaltered (1.9 +/- 0.2) over the entire concentration range of MnCl2 tested.

4-Nitrophenylphosphatase↗
PubMed1984

Effect of interaction of heavy metals on (Na+ -K+) ATPase and the uptake of 3H-DA and 3H-NA in rat brain synaptosomes.

The effect of interaction of Mn2+, Pb2+ and Cd2+ on (Na+ -K+) ATPase and uptake of labelled dopamine (3H-DA) and labelled noradrenaline (3H-NA) were studied in vitro in rat brain synaptosomes. The inhibition of (Na+ -K+) ATPase by Pb2+ and Cd2+ alone was concentration dependent, however, Mn2+ had almost no effect on the activity of this enzyme. Interaction of Cd2+ with either Pb2+ or Mn2+ was most powerful in inhibiting the activity of synaptosomal transport ATPase. Lower concentrations of Pb2+ increased while higher concentrations inhibited synaptosomal uptake of 3H-DA and 3H-NA. Lower concentrations of Cd2+ increased the uptake of 3H-DA while at concentrations of 100 microM, the uptake was inhibited, this metal had strong inhibitory effect on the uptake of 3H-NA. Mn2+ had inhibited the uptake of labelled amines. Interaction of Mn2+ with Pb2+ or Cd2+ produced inhibition on the uptake of 3H-DA and 3H-NA. The results of the uptake of biogenic amines in the presence of metal ions apparently had no correlation with the activity of (Na+ -K+) ATPase which is involved in the active transport of cations across cell membranes.

Animals↗
PubMed1982

Air monitoring network program in Saudi Arabia.

The Kingdom of Saudi Arabia has initiated a program to install air quality network stations throughout the country in order to measure concentration of the ambient air pollutants. The site selection of these stations is an important objective to be accomplished and must be done based on scientific and rational work. To accomplish this objective, a modified version of atmospheric transport and dispersion model, known as air resources laboratories - atmospheric transport and dispersion (ARL- ATAD) model, is used to evaluate long range transport and diffusion of air pollutants from major pollution causing sources such as refineries, open-air burning of associated gases of oil fields and major industries. Hourly meteorological data for a period of three years (from 1977 to 1979) on wind speed, wind direction, pressure, and temperature from 20 synoptic stations in Saudi Arabia is processed and used as model input. In addition to these, meteorological data from three upper air stations is also processed in order to determine base and top of critical inversion heights. Various pollution causing sources are identified within the study area. Air trajectories are drawn with sources as the origins of the trajectories and the dispersion characteristics is studied with distance and time. Based on long term meteorological records, the adversely affected zones are statistically identified for potential station sites.

Air Pollution↗
PubMedDate not supplied

Pneumoconiosis risk assessment in agate workers--multiple logistic model.

A multivariate logistic model for measuring and comparing pneumoconiosis risk is described. In the first stage variables are screened on the basis of contributed variability via Pearson Chi Square statistic. Age, dust years and pack years so chosen as explanatory variables are fitted in the above model. The coefficients are estimated as linear discriminant function co-efficient. The model gives quite a good fit between observed and expected frequencies. Dust years discriminate maximum between the normal and pneumoconiosis group. Nearly sixty per cent of the variation is explained by these variables.

Adult↗