A comparative study of some methods for measuring carbon monoxide in air.

The present study aimed at comparing between some physical and chemical methods for measuring carbon monoxide (CO) level in air and selecting the most suitable one concerning simplicity, reproducibility, sensitivity, specificity, and accuracy. Known concentrations of CO were prepared in cylinders and air samples with unknown concentrations of CO were collected in plastic bags from the street environment. Both known and unknown concentrations of CO were measured by four selected methods. The leucocrystal violet method was found suitable only for levels of CO higher than 40 ppm and not recommended for ambient levels. The iodine pentoxide method was suitable for any level of CO in air but only for grab samples. The combustion method was also suitable for any level of CO above 10 ppm and for grab and continuous samples. MIRAN-IA analyzer is an infrared instrument, is very simple, sensitive and accurate for concentrations of 10 ppm and above. Other types of infrared analyzers may give higher accuracy and sensitivity levels at lower concentrations.

Indoor air pollution and acute lower respiratory infections in the first two years of life.

The relationship between outdoor air pollution and acute respiratory infections (ARI) was previously documented. There are recent indications for connection between indoor air pollution and ARI in infants and young children. The aim of this study was to identify the relationship of indoor air pollutants to acute lower respiratory infection (ALRI) in children (< 2 years). The indoor air pollutants concentrations were measured in the homes of the sample. The sample consisted of 115 children (< 2 years) representing the control group (24), ALRI but no pneumonia (24), pneumonia (30), severe pneumonia or very severe disease (37). Air sampling was performed to measure the concentration of total suspended particulates (TSP), SO2 and CO. These pollutants were found in higher concentrations in cases' homes (52.46 +/- 19.68 microg/m3, 298.15 +/- 669.37 microg/m3, and 1.92 +/- 3.60 ppm) than in controls' homes (31.92 +/- 8.76 microg/m3, not detected, and 0.33 +/- 1.63 ppm respectively). Whereas SO2 was detected only in houses using kerosene, TSP and CO were detected with the different types of cooking fuels. Their mean concentrations were highest for biomass (88.86 +/- 13.30 microg/m3 and 9.29 +/- 2.50 ppm) and lowest for gas (40.78 +/- 15.25 microg/m3 and 0.76 +/- 2.19 ppm). Measures to improve indoor air quality are highly required.

A comparative environmental and medical study of dust exposure in jute and cotton mills in Burma.

Jute is extensively cultivated and processed in Burma, as well as "lower-grade" cotton. This study was conducted there to compare dust exposure in jute and cotton mills, to study the acute and chronic effects of dust exposure on workers, and to establish exposure-response relationship. A sample of 799 male and female workers in two jute mills and two cotton textile mills, as well as a control group of 153 matching subjects, was examined, and dust exposure in the work environment was evaluated. Very high dust concentrations existed in the early stages of jute processing and sorting, which were reduced when jute fibers got cleaner, as in drawing and spinning, and were related to the grade of the processed fiber. Much lower concentrations of dust existed in the cotton mills, but exceeded the TLV (ACGIH) only in opening and cleaning and in carding operations. However, byssinosis occurred only in workers exposed to cotton dust, particularly among males, and its prevalence was related to the level and duration of dust exposure. Chronic bronchitis, cough and wheezing occurred at higher rates among all workers than in the control, while irritation to nose and throat, eyes and skin prevailed only among jute workers. A significant reduction in FVC, FEV1.0 and PEF (before and during shift) was observed in workers compared to control subjects, and was related to workers' exposure and age; however, this reduction was not related to symptoms of different respiratory conditions. "Cheroots" smoking was found to be an important potentiating factor in the occurrence of non-specific respiratory diseases and reduction in FEV1.0, particularly among jute workers.

Study of the role of airborne lead in food chain of crops grown around a main highway in Egypt.

The present study was conducted to clarify the fate of airborne lead derived from petrol and its role in the food chain of tomato cultivated in lead-contaminated-soil. Settled dust was sampled at 4 stations at 7, 75, 150 and 500 meters from Alexandria/Cairo highway, and analysed for lead, sulfate and nitrate. Tomato fruits--and plants--were harvested at the sampling sites and analysed for lead. Settled dust and lead content steadily decreased by distance from the highway, indicating that traffic derived lead aggregates with other pollutants in particles and settle at distance of a few hundred meters. The lead tends to be evenly distributed in aggregates of different particle sizes, while the sulfate and nitrate tend to concentrate in medium-sized aggregates. The lead in plants of different stages of growth correlated with that in the dust, and was the highest in fruit and roots. Lead contamination of the plant had an impact on tomato crop reduction. The levels of lead in tomato fruits were 17.7 ppm in the samples collected at 7-500 meters from the highway, while the legal limit for lead in food is 1 ppm.

Study of the lipoprotein pattern among workers exposed to lead.

Occupational exposure to lead fumes constitutes a serious problem in Egypt, since a considerable number of workers might be involved in its deleterious effect. The present study aimed to elucidate the effect of lead exposure on the lipoprotein pattern of exposed workers. The study has been carried out in a plant manufacturing lead batteries. It consists of 89 workers exposed to lead and 25 control subjects. Fasting blood samples were collected for the determination of serum lipoprotein pattern and their cholesterol and phospholipid content. Levels of lead in blood and delta amino levulinic acid in urine have been determined as biological indices of lead exposure. Lead exposure caused mainly a cumulative effect on the cholesterol and phospholipid content of lipoproteins since only workers exposed for more than 10 years showed significant changes. These changes might be referred to the effect of lead exposure on liver and/or on trace metal metabolism.

An environmental and medical study of byssinosis and other respiratory conditions in the cotton textile industry in Egypt.

This study was conducted in a typical Egyptian textile plant located in Alexandria. Male workers from all operations (N = 506) were examined and their dust exposures were assessed. Results showed that airborne dust concentrations were very high and that the plant fraction is mostly concentrated in respirable dust. Byssinosis prevailed in 21% of workers in opening and cleaning sections and in 13% in carding and combing rooms, but was found in none of the workers in drawing, twisting, and spinning operations, in only 1.1% in weaving, and in 3.1% of workers in other "auxiliary" occupations. The rare prevalence of byssinosis among the latter workers' groups was attributed to the workers' continuous exposure without fixed weekend interruption, the personal and family history of exposure to cotton, the low proportion of plant materials in dust evolved in related operations, the fine quality of Egyptian cotton, and/or the population characteristics of Egyptian workers. Reduction in FEV 1.0 at the end of the first work shift after absence from work occured more often than byssinosis, which indicates the importance of this test for the early detection of effects of cotton dust exposure. It is suggested that a nationwide study in the cotton textile industry is indicated.