[Determination of susceptibility to heat-related disorders and prevention methods among agriculture workers]

Workers employed in outdoor occupations such as farm working, especially during rice harvest, are exposed to hot and humid environments that put them at risk for different kinds of heat-related disorders or heat stress. The aim of this study was to determine the susceptibility to heat-related disorders and prevention methods among a group of agriculture workers in one of the northern cities in Iran. This study is a descriptive-analytical and cross-sectional study which was done among 340 agricultures workers in a city [Sorkhrood] in Mazandaran province. The samples were collected from 42 villages using two stage cluster-randomized sampling method. The data were collected by means of tailor-made data collection sheet and analyzed using descriptive statistical indexes and Chi- square test, and p<0.05 was considered as significant. The findings indicated that the mean values of age and years of experience were 42.8 and 26 years, respectively. Almost half of the agriculture workers were overweight or obese, 34% illiterate, and 15% encountered chronic illnesses. Ninety five percent of the workers were not informed about prehydration in hot environment and none of them know about the consumption of electrolytes. According to Chi-square test result, there were no significant differences between the prevalence of headache as one of the early signs of heat -related disorders and other related factors. According to the results, agriculture workers based on their age distribution, education, body mass index, health knowledge, drug use and incidence of chronic diseases, are very vulnerable to heat-related disorders. Therefore, training on recognizing the early signs and doing control measures as essential element in heat stress prevention should be seriously considered

Removal of airborne hexavalent chromium using alginate as a biosorbent

Airborne hexavalent chromium has been classified as a human respiratory carcinogen and long term exposure has been known to cause ulceration and perforation of the nasal septum, bronchitis, asthma, and liver and kidney damage. Chromium electroplating plants are the major sources of atmospheric chromium and packed-bed scrubbers are the common control devices used to reduce emission of chromic acid mist from electroplating bathes. The feasibility of a new method to remove this pollutant using alginate beads as a biomass derivative was investigated by one factor at a time approach and Taguchi experimental design. Polluted air with different chromium mist concentrations [10-5000 micro g/m3] was contacted to alginate beads [3.3-20 g/L], floating in distilled water with adjusted pH [3-7], using an impinger at different temperatures [20 and 35°C], and various velocities [1.2 and 2.4 m/s]. Although there were no statistical significant differences between factor levels, the higher ions removal efficiencies were achieved at lower levels of air velocities, pollution concentrations, higher levels of pHs, temperatures, and sorbent concentrations

[Design, construction and performance of chromium mist generator]

The chromium mist generator is an essential tool for research and for making evidence-based recommendations in evaluating air pollution and its control systems. The purpose of this study was to design and construct a homogeneous chromium mist generator and to look at the effects of factors such as sampling height and distance between samplers in side-by-side sampling on the chromium mist sampling method. First we developed a mist generator, using a chromium electroplating bath in pilot scale. Concentrations of CrO3 and sulfuric acid in plating solution were 125 g L-1 and 1.25 g L-1, respectively. To set up permanent air sampling locations, a Plexiglas cylindrical chamber [75 cm height, 55 cm i.d] was installed as the bath overhead. Sixty holes were made on the chamber in 3 rows [20 in each row]. The distance between rows and holes was 15 and 7.5 cm, respectively. Homogeneity and the related factors were studied using a side-by-side air sampling method. Forty-eight clusters of samples were collected on polyvinyl chloride [PVC] filters contained in sampling closed-face cassettes. Cassettes were located 35, 50, and 65 cm above the solution surface with < 7.5 and/or 7.5-15 cm distance between heads. All samples were analyzed by the NIOSH method 7600. ANOVA tests showed no significant differences between locations in side-by-side sampling [P=0.82] or between different sampling heights or sampler distances [P=0.86 and 0.86, respectively]. However, there were notable differences between means of coefficients of variation [CV] in various heights and distances. We conclude that the most chromium mist homogeneity could be obtained at a height of 50 cm from the bath solution surface and with a distance of < 7.5 cm between samplers

Removal of airborne hexavalent chromium mist using chitosan gel beads as a new control approach

Airborne hexavalent chromium is a known human respiratory carcinogen and allergen. Many workers are exposed to hexavalent chromium in various processes which chromium electroplating plants are the most common. In this study, the feasibility of a new control approach to remove this pollutant using chitosan beads as a biosorbent was investigated. Hexavalent chromium sorption was studied relative to pH, pollution concentration, sorbent concentration, temperature, and air velocity using one factor at a time approach and Taguchi experimental design. Polluted air with different chromium mist concentrations [10-5000 micro g/m[3]] was contacted to chitosan beads [3.3-20 g/L], floating in distilled water with adjusted pH [3-7], using an impinger at different temperatures [20 and 35 °C], and various velocities [1.12 and 2.24 m/s]. The ANOVA test result showed that, there were statistical significant differences between factor levels except optimized pH levels. The higher ions removal efficiencies were achieved at lower levels of air velocities, pollution concentrations, and higher levels of solution pH values, temperatures, and sorbent concentrations

Assessment of worker's exposure to heavy metals in zinc melting industry, Zanjan, Iran, 2004-2005

Heavy metal emission to the workplace and environment is a major health problem due to human activity posing a serious threat to the public especially to those working in manufacturing industries and consumers. Thus, this study was conducted with the aim of extent of worker's exposure to heavy metals in zinc melting industry in Zanjan during 2002-2004. This descriptional study was conducted in 6 industrial units of Zanjan through which airborne heavy metals concentrations including lead, zinc, cobalt, cadmium and nickel were measured. Measurements were performed based on National Institute of Occupational Health [NIOSH] 7300 method, using closed-filter cassettes, ester cellulose filter with pore size of 0.8 micro m followed by atomic absorption spectrometry [AAS] analysis, and the data were analyzed statistically using SPSS software version 11.5. The mean value of worker's exposure to heavy metals including Pb, Zn, Co, Cd, and Ni were 0.058, 2.518, 0.0025, 0.003, and 0.0108 mg/m[3] respectively. According to the obtained results 25% of the workers were exposed to lead higher than threshold limit values [TLVS]. However, worker's exposure to combined concentrations of different heavy metals [heavy metal mixed exposure] showed that more than 75% of the workers were exposed to heavy metals concentrations higher than TLV. In spite of short history of zinc melting industry in Zanjan [under 15 years] and young age of workforce, exposure of many workers to heavy metals concentration of higher than standard value increases the possibility of occupational diseases in the coming years. Thus, in order to protect national and human resources, preventive measures such as worker's health monitoring and control techniques are highly recommended