Effect of noise on human performance under variable load in a die casting industry--a case study.

The manual mode of working in industries is very common in the developing and under developed countries. Many industrial processes have generated high levels of noise and causing physiological effects on operators and thus leading to reduced performance. A survey was carried in various die casting industries to determine the levels of noise. It was found that the levels were in the range of 80-100dB(A). The survey also showed that the effects were more pronounced when the task was conducted under varying load conditions. Keeping this in view the problem was formulated to study whether the level of noise and amount of load has a bearing on human performance. For this purpose, experimental investigations in a simulated environment were carried out. Five subjects, all males and having no experience in the trade were selected for the task. The levels of noise under taken were 80, 90 and 100 dB(A) while the levels of load were 150, 200 and 250 N. A pulse oximeter was used to measure the human performance in terms of heart rate. The data was collected and analyzed on the basis of two factor repeated measure type of experimental design. Results of the study indicated that the level of noise and load both were having statistically significant effect on human performance. However, the interaction of level of noise and load was found to be statistically non-significant. The findings of the present work have been discussed in the light of the previous researches carried out on the topic. Suggestions have been made to reduce the levels of noise as per the recommendations of Occupational Safety and Health Association (1990). It is also suggested that instead of hand operated machines, foot operated versions should be used to reduce fatigue.

Effect of dietary garlic (Allium Sativum) on the blood pressure in humans--a pilot study.

OBJECTIVE: To find out whether individuals with blood pressures on the lower side consume more garlic in their diets. A pilot study to make grounds for more elaborate future trials. METHOD: A questionnaire was developed in order to estimate the dietary intake of garlic per person per month and to record three blood pressure readings on each individual. It was administered to 101 adult subjects, presenting to the Family Practice Centre of a hospital in the city of Karachi, Pakistan. The various demographic parameters including age, sex, marital status and education were recorded. Those subjects found to be overweight, with known history of hypertension, diabetes mellitus, ischaemic heart disease, and smoking and on medications, which effect blood pressure, were excluded from the study. This was done to remove the effect of confounding variables on Blood Pressure. The data was entered into the epi-info program and the analysis was done using the SPSS software. RESULTS: An average garlic use of 134 grams per case per month was found. 67% of the subjects used garlic in cooked food while the rest used either in the raw form or in pickles. 59% thought that dietary use of garlic is healthy. Subjects with blood pressure on the lower side are found to consume more garlic in their diets. (The mean difference is significant for systolic with p value of 0.05). CONCLUSION: This study shows that individuals whose blood pressures are on the lower side are more likely to consume more garlic in their diets. (Statistically significant for systolic blood pressure only). This was a pilot study and more elaborate trials are recommended to prove this association.

HIV antibody seroprevalence and associated risk factors in sex workers, drug users, and prisoners in Sindh, Pakistan.

OBJECTIVE: To determine prevalence of HIV infection and risk behaviors in commercial sex workers (CSWs), drug users, and prisoners in Sindh, Pakistan. METHODS: A medical clinic was established in a "red-light" district of Karachi. Eighty-one CSWs who registered at the clinic between November 1993 and June 1994 were provided HIV counseling and testing and administered a risk factor questionnaire. Next, 316 male drug users were tested for HIV-1 antibody from April to July 1994. Finally, a voluntary serosurvey of HIV-1 and HIV-2 and risk behaviors of 3525 prisoners in Sindh was conducted between July 1994 and December 1994. Abbott Recombinant HIV third-generation enzyme-linked immunosorbent assay (ELISA) and confirmatory testing with Western blot analysis were used in all three groups. RESULTS: None of 81 CSWs tested for HIV-1 antibody were positive. None of 316 drug users tested positive for HIV-1 antibody. Of 3441 male prisoners, 1 was HIV-1 infected, and of 84 female prisoners, 1 was HIV-1 infected. No prisoner was positive for HIV-2 antibody. DISCUSSION: The prevalence of HIV in CSWs, drug users, and prisoners in Sindh is low at present. Intervention programs implemented at this stage can make an impact in HIV prevention.

PIP: A three-stage study conducted in Pakistan's Sindh province in 1993-94 investigated HIV seroprevalence in commercial sex workers, drug users, and prisoners. First, the 81 sex workers who registered at a medical clinic established in a "red light" district in Karachi in a 7-month period were provided HIV counseling and testing and administered a risk factor questionnaire. Second, 316 male drug users who presented to a charitable drug rehabilitation center over a 3-month period (n = 202) or were arrested in a drug raid and sent to the center (n = 114) were tested. The third stage entailed voluntary HIV-1 and -2 testing and a risk factor questionnaire for 3525 prisoners. Recombinant HIV third-generation enzyme-linked immunosorbent assay with confirmatory testing by Western blot were used in all three groups. There were no cases of HIV-1 infection among either sex workers or drug users. HIV-1 antibody was present in 1 of the 3441 male prisoners and 1 of the 84 female prisoners. The infected male prisoner reported multiple encounters with sex workers in Bombay in 1990; the only identifiable risk factor in the HIV-positive female prisoner was several injections at the prison dispensary with reused syringes. No prisoner was positive for HIV-2 antibody. 65% of the sex workers used no contraception and condom use was negligible. 52% of injecting drug users shared needles. 22% of the male prisoners reported sexual relations with men prior to incarceration. Of concern was the finding that 26% of drug users and 23% of prisoners were paid blood donors. The low prevalence of HIV in high-risk groups in Pakistan, despite an alarming incidence of high-risk behaviors, provides a window of opportunity for implementation of AIDS prevention programs.

Regional effects of sulfur dioxide exposure on the guinea pig brain lipids, lipid peroxidation and lipase activity.

Experiments to evaluate the neurochemical action of gaseous pollutants were performed in a specifically designed inhalation chamber. Exposure of guinea pigs to 10 ppm of SO2 for one hour daily for 21 days produced a significant depletion of total lipids and free fatty acids in all brain regions. Phospholipid and cholesterol content of the cerebellum and brain stem were also decreased, but were increased in cerebral hemisphere. Esterified fatty acids were depleted in the cerebral hemisphere and brain stem, but exhibited increment in the cerebellum. The rate of lipid peroxidation and the activity of lipase were increased significantly in all the regions of the brain. The results clearly indicate that SO2-exposure induces degradation of brain lipids. Interestingly, the lipid contents are affected differentially in the various parts of the brain.