Quantitative and Semiquantitative Health Risk Assessment of Occupational Exposure to Styrene in a Petrochemical Industry

Background@#Styrene is one of the aromatic compounds used in acetonitrile–butadiene–styrene (ABS) producing petrochemicals, which has an impact on health of workers. Therefore, this study aimed to investigate the health risks of styrene emitted from the petrochemical industry in Iran. @*Methods@#Air samples were collected based on NIOSH 1501 method. The samples were analyzed by the Varian-cp3800 gas chromatograph. Finally, risk levels of styrene's health effects on employees were assessed by the quantitative method of the U.S. Environmental Protection Agency (U.S. EPA) and the semiquantitative way by the Singapore Occupational Safety and Health Association. @*Results@#Based on the results, the employees had the highest average exposure to styrene vapors (4.06x10-1 mg.(kg - day)-1) in the polybutadiene latex (PBL) unit. Therefore, the most top predictors of cancer and non-cancer risk were 2.3x10-4 and 7.26x10-1, respectively. Given that the lowest average exposure (1.5x10-2mg.(kg - day)-1) was in the dryer unit, the prediction showed a moderate risk of cancer (0.8x10-6) and non-cancer (2.3x10-3) for the employees. The EPA method also predicted that there would be a definite cancer risk in 16% and a probable risk in 76% of exposures. However, according to the semiquantitative approach, the rate of risk was at the “low” level for all staff. The results showed that there was a significant difference (p < 0.05) between the units in exposure and health risk of styrene (p < 0.05). @*Conclusion@#Given the high risk of styrene's health effects, appropriate control measures are required to reduce the exposure level.

Quantitative and Semiquantitative Health Risk Assessment of Occupational Exposure to Styrene in a Petrochemical Industry

Background@#Styrene is one of the aromatic compounds used in acetonitrile–butadiene–styrene (ABS) producing petrochemicals, which has an impact on health of workers. Therefore, this study aimed to investigate the health risks of styrene emitted from the petrochemical industry in Iran. @*Methods@#Air samples were collected based on NIOSH 1501 method. The samples were analyzed by the Varian-cp3800 gas chromatograph. Finally, risk levels of styrene's health effects on employees were assessed by the quantitative method of the U.S. Environmental Protection Agency (U.S. EPA) and the semiquantitative way by the Singapore Occupational Safety and Health Association. @*Results@#Based on the results, the employees had the highest average exposure to styrene vapors (4.06x10-1 mg.(kg - day)-1) in the polybutadiene latex (PBL) unit. Therefore, the most top predictors of cancer and non-cancer risk were 2.3x10-4 and 7.26x10-1, respectively. Given that the lowest average exposure (1.5x10-2mg.(kg - day)-1) was in the dryer unit, the prediction showed a moderate risk of cancer (0.8x10-6) and non-cancer (2.3x10-3) for the employees. The EPA method also predicted that there would be a definite cancer risk in 16% and a probable risk in 76% of exposures. However, according to the semiquantitative approach, the rate of risk was at the “low” level for all staff. The results showed that there was a significant difference (p < 0.05) between the units in exposure and health risk of styrene (p < 0.05). @*Conclusion@#Given the high risk of styrene's health effects, appropriate control measures are required to reduce the exposure level.

Development and validation of an environmental heat strain risk assessment (EHSRA) index using structural equation modeling based on empirical relations

BACKGROUND@#Need to a simple, available, accurate, comprehensive, and valid indicator is felt to assess thermal effects. Therefore, the present study was aimed to develop and validate the environmental heat strain risk assessment (EHSRA) index using structural equation modeling (SEM) based on empirical relations.@*METHODS@#This cross-sectional study was performed on 201 male workers in environments with various climatic conditions. The heart rate and tympanic temperature of the individuals were monitored at times of 30, 60, and 90 min after beginning the work. At these times, values of dry temperature, wet temperature, globe temperature, and air velocity were also measured and metabolism rate and clothing thermal insulation value were estimated. At the end, a theoretical model was depicted in AMOS software and obtained coefficients were applied to develop a novel index. The scores of this indicator were categorized into four risk levels via ROC curves and validate using linear regression analysis.@*RESULTS@#Indirect effect coefficients of the globe temperature, dry temperature, wet temperature, air velocity, metabolism, and clothing thermal insulation variables on the tympanic temperature were computed by 0.77, 0.75, 0.69, 0.24, 0.49, and 0.39, respectively. These coefficients were applied to develop the index. Optimal cut-off points of boundaries between risk levels included 12.02, 15.88, and 17.56. The results showed that the EHSRA index justified 75% of the variations of the tympanic temperature (R@*CONCLUSIONS@#The novel index possesses appropriate validity. It was suggested that this indicator is applied and validated in various environments in the next studies.

Assessment of Semen Quality among Workers Exposed to Heat Stress: A Cross-Sectional Study in a Steel Industry

BACKGROUND: This study was conducted to investigate the heat stress and semen quality among male workers in a steel industry in Iran and investigate the relationship between heat stress indices and semen parameters. METHODS: The study was conducted on workers exposed (n = 30) and unexposed (n = 14) to heat in a steel industry. After obtaining a brief biography of the selected employees, scrotal temperature, oral temperature, and environmental parameters were measured, and their semen samples were analyzed according to the procedure recommended by the World Health Organization. The heat stress indices, including wet-bulb globe temperature (WBGT) and predicted heat strain (PHS), in their workplace were calculated according to environmental parameters (ISO 7243:1989 and 7933:2004, respectively). RESULTS: Time-weighted averages of WBGT and PHS (35.76°C and 491.56 w/m2 w m 2 , respectively) for the exposed group were higher than threshold limit values. The mean difference of environmental, physiological, and semen parameters (exception: pH of semen), and also WBGT and PHS indices were statistically significant (p < 0.05) between the two groups. Mean semen parameters were in the normozoospermic range. WBGT and PHS indices showed significantly “negative” correlation with physiological parameters (scrotal and oral temperature) and most semen parameters (semen volume, sperm morphology, sperm motility, sperm count; p < 0.05); moreover, the correlation of WBGT with these parameters was stronger than PHS. CONCLUSION: Semen parameters of the studied workers exposed to heat were in the borderline level of normozoospermic range, and their semen parameters were significantly lower than controls. For better assessment of occupational environment concerning physiological and semen parameters in steel industries, WBGT can be a more useful index.

Validating the heat stress indices for using in heavy work activities in hot and dry climates

Background: Necessity of evaluating heat stress in the workplace, require validation of indices and selection optimal index

The present study aimed to assess the precision and validity of some heat stress indices and select the optimum index for using in heavy work activities in hot and dry climates

Methods: It carried out on 184 workers from 40 brick kilns workshops in the city of Qom, central Iran [as representative hot and dry climates]

After reviewing the working process and evaluation the activity of workers and the type of work, environmental and physiological parameters according to standards recommended by International Organization for Standardization [ISO] including ISO 7243 and ISO 9886 were measured and indices were calculated

Results: Workers engaged in indoor kiln experienced the highest values of natural wet temperature, dry temperature, globe temperature and relative humidity among studied sections [P<0.05]

Indoor workplaces had the higher levels of all environmental parameters than outdoors [P=0.0001], except for air velocity

The wet-bulb globe temperature [WBGT], predicted heat strain [PHS] and heat stress index [HSI] indices had the highest correlation with the physiological parameters. Relationship between WBGT index and carotid artery temperature [r=0.49], skin temperature [r=0.319], and oral temperature [r=0.203] was statistically significant [P=0.006]

Conclusions: Since WBGT index, as the most applicable index for evaluating heat stress in workplaces is approved by ISO, and due to the positive features of WBGT such as ease of measurement and calculation, and with respect to some limitation in application of HSI; WBGT can be introduced as the most valid empirical index of heat stress in the brick workshops

Determination of air enthalpy based on meteorological data as an indicator for heat stress assessment in occupational outdoor environments, a field study in Iran

Background: Heat stress evaluation and timely notification, especially using meteorological data is an important issue attracted attention in recent years

Therefore, this study aimed at answering the following research questions: 1] can enthalpy as a common environmental parameter reported by meteorological agencies be applied accurately for evaluation of thermal condition of outdoor settings, and 2] if so, what is it's the best criterion to detect areas in stress or stress-free situations, separately

Methods: Nine climatic regions were selected throughout Iran covering a wide variety of climatic conditions like those, which exist around the world. Three types of parameters including measured [ta, RH, Pa and WBGT], estimated [metabolic rate and cloth thermal insulation], and calculated parameters [enthalpy and effective WBGT] were recorded for 1452 different situations. Enthalpy as a new indicator in this research was compared to WBGT in selected regions

Results: Altogether, a good consistency was obtained between enthalpy and WBGT in selected regions [Kappa value: 0.815]. Based on the good ROC curve obtained using MedCal software, the criterion of the values more than 74.24 for the new index was determined to explain heat stress situation for outdoor environments

Conclusions: Because of simplicity in measurement, applicability of the indicator for weather agencies, the consistency observed between enthalpy and a valid as well as accurate index [WBGT], sensor requirements which take only a few seconds to reach equilibrium and so on, enthalpy indicator can be introduced and applied as a good substitute for WBGT for outdoor settings

Investigation of heat stress and heat strain in outdoor workers: a case study in Iran

Heat stress is an important and serious threat at work and is a particular concern in outdoor occupational environments. This study aims at comparing heat stress and heat strain at different outdoor groups, examining the protective and adaptive actions which were done by workers and also provi services to them by government or employer to reduce heat load. This cross-sectional study was conducted in the hottest days of the summer 2015 in Shabestar, Iran and 53 healthy men in nine occupational groups including concrete makers, porters, construction, waste site and road making workers, stonemasons, farmers, traffic officers, and street vendors participated. A set of physiological parameters, like heart rate, blood pressure, skin temperature and etc., WBGT index details and some of the adaptive and protective parameters were measured and monitored simultaneously at different times of the day. The study finds that heat exposure in outdoor workplace is prevalent and WBGT TWA/TLVave is less than 1 in some groups like stonemasons, waste site workers, traffic officers and street vendors whereas in other studied occupations, it is more than 1.This matter is compounded by the fact that the provision of health services by employers or local government was limited, and almost all of the participants had poor or insufficient access levels to public health and welfare services. This study confirms the necessity of interventions by a range of factors, such as government plans, improvement of services in the prevention of heat stress, and planning training courses for outdoor workers to build their knowledge of heat stress

Relationship between oral temperature and sleepiness among night workers in a hot industry

Night work can have a significant impact on health, well-being, performance and occupational safety of workers. Night workers often complain about the sleep disorder characterized by excessive sleepiness. The aim of the study was to determine the level of sleepiness among night workers and investigate its relationship with oral temperature in a hot industry. This cross-sectional study involved 80 night workers. Stanford Sleepiness Scale [SSS] has been used to measure the level of sleepiness. Oral temperature and SSS were recorded at different hours of night shift [23 pm to 4 am] for two consecutive nights. The analysis of results showed that there was a positive linear trend in the sleepiness scale [Pvalue<0.001] and an increasing trend in the oral temperature between 23pm and 1am. Then a decreasing trend has been observed after 1am for both of them [Pvalue <0.001]. Comparison of the results for two nights indicated that the mean sleepiness index in the second night is higher than the first [Pvalue <0.001], but the mean oral temperature in the second night was equal to that in the first night. Findings suggest a weak negative association between sleepiness and oral temperature. [r=-0.24, Pvalue =0.03]. A substantial proportion of subjects were working while sleepy, especially at late night and early morning hours. The combination of heat stress and sleepiness can lead to impaired performance. The growing amount of sleepiness index indicates the high risk of sleep disorders and the other possible problems related health among night shift workers

Heat stress and physical capacity: a case study of semi-professional footballers

The aim of this study was to determine heat stress effect on physical capacity of semi-professional footballers in Iran by means of oxygen consumption measurement, heart rate monitoring and WBGT assessment environmental conditions. This study compared two different thermal environmental conditions related to sub-maximal exercise and its effect on human physical capacity. Thirty two male footballers [age 25.9 +/- 1.4 year; height 176 +/- 2.9 cm and weight 71 +/- 9.8 kg] were investigated under four workloads [50,100,150 and 200 W] in two different thermal conditions in the morning [WBGT=21°C] and afternoon [WBGT=33°C] in summer. Each test cycle lasted for 10 minutes with a 10 min interval for recovery and rest between every workload. In the end of each stage, the heart rate, blood pressure, skin temperature and oral temperature were measured and recorded. Expired air was collected and its volume was measured using standard Douglas bags. The WBGT index was also used to monitor the stressful heat condition. Heart rate and VO[2] consumption findings for different workload showed a significant difference between morning and afternoon [P<0.001]. HR and VO[2] consumption in both morning and afternoon courses showed a liner relation [r=0.88, r=0.9 respectively]. With increasing work load beside heat stress, heart rate and oxygen consumption increased. It is recommended that with Ta>35°C or WBGT>28°C, physical activates and performing exercises should be avoided in order to reduce the risk of heat stress-related conditions in athletes

Occupational exposure to mercury: air exposure assessment and biological monitoring based on dispersive ionic liquid-liquid microextraction

Exposure to mercury [Hg] as a heavy metal can cause health effects. The objective of this study was to assess occupational exposure to Hg in a chlor-alkali petrochemical industry in Iran by determining of Hg concentrations in air, blood and urine samples. The study was performed on 50 exposed subjects and 50 unexposed controls. Air samples were collected in the breathing zone of exposed subjects, using hopcalite sorbents. Analysis was performed using a cold vapor atomic absorption spectrophotometer [CV-AAS] according to NIOSH analytical method 6009. For all participants, blood and urine samples were collected and then transferred into sterile glass tubes. After micro-extraction with ionic liquid and back extraction with nitric acid, Hg concentrations in blood and urine samples were determined by CV-AAS. The mean concentration of air Hg was 0.042 +/- 0.003 mg/m[3]. The mean concentrations of Hg in blood and urine samples of exposed subjects were significantly higher than unexposed controls [22.41 +/- 12.58 versus 1.19 +/- 0.95 micro g/l and 30.61 +/- 10.86 versus 1.99 +/- 1.34 micro g/g creatinine, respectively]. Correlation of air Hg with blood Hg, urine Hg and blood Hg-urine Hg ratio were significant statistically [P< 0.05]. The values of Hg in blood and urine samples of chlor-alkali workers were considerably high. Correlation coefficients showed that blood Hg and blood Hg-urine Hg ratio are better indicators than urine Hg for assessing occupationally exposed workers in terms of current exposure assessment

[ study of the association between oral temperature and sleepiness among night-shift workers in a glass industry]

Night-shift work has adverse effects on workers' health, productivity, and occupational safety. Night workers have complaints about sleepiness, decreased performance, and sleep disorders, due to disruption of circadian rhythm function. This research aimed to determine the level and process of sleepiness among night workers of a hot industry and evaluate its correlation with oral temperature. This study was performed as a cross-sectional study on 80 night-shift workers who were exposed to heat. The sleepiness level of the subjects was measured by Stanford Sleepiness Scale and their oral temperature were recorded at different hours [from 22 pm to 4 am] for two consecutive nights. Data analysis was performed using independent and paired t-tests, one-way ANOVA, repeated measures ANOVA, and Pearson correlation coefficient. The significance level was considered to be p<0.05. In this study, an increasing linear trend over time was obsereved for sleepiness index [p<0.001]. The mean of oral temperature had an increasing trend from 11 pm to 1 am and a decreasing trend afterward [p<0.001]. Also, the mean sleepiness index in the measurement hours of the second night was higher than that of the first night [p<0.001], but, the mean oral temperature in the second night was onsistent with the results obtained in the first night. The sleepiness index among night-shift workers was significantly decreased with increasing oral temperature [r=0.24, p=0.03]. According to the findings of this study, there was an inverse correlation between sleepiness and oral temperature after a few hours of exposure to heat. In this study, sleepiness symptoms were subjectively recorded based on the workers' self-expression; therefore, it is suggested that paraclinical trials, such as hormonal assessments be considered

Evaluation of occupational exposure of glazers of a ceramic industry to cobalt blue dye

Cobalt is one of the most important constituent present in ceramic industries. Glazers are the relevant workers when they are producing blue colored ceramic, causing occupational exposure to such metal. Through this study, urinary cobalt was determined in glazers in a ceramic industry when they were producing blue-colored ceramic glazes. In this case-control study, spot urine samples were collected from 49 glazers at the start and end of work shifts [totally 98 samples] in 2011. Control group were well matched for age, height, and weight. A solid phase extraction system was used for separation and preconcentration of samples followed by analysis by inductively coupled plasma-atomic emission spectroscopy [ICP-AES]. All participants filled out a self administered questionnaire comprises questions about duration of exposure, work shift, use of mask, skin dermatitis, kind of job, ventilation system, overtime work, age, weight, and height. The lung function tests were performed on each control and cobalt exposed subjects. Analysis of covariance [ANCOVA] was used to evaluate the obtained results. Urinary levels of cobalt were significantly higher in the glazers compared to the control group. There were significant differences at urinary concentration of cobalt at the start and end of the work shift in glazers. Spirometric parameters were significantly lower in the glazers compared to the control group. Among the variables used in questionnaire the significant variables were dermatitis skin, mask, ventilation, and overtime work. This study verified existence of cobalt in the urine glazers showing lower amount than the ACGIH standard

Designating smoking room to control environmental tobacco smoke in nursing homes

This study was initiated to assess the effectiveness of designating smoking rooms to control environmental tobacco smoke in nursing homes. Of the 39 nursing homes located in Toledo [a city in Ohio, USA] included in the preliminary survey, 33 facilities [85%] allowed smoking, 14 facilities [36%] allowed indoor smoking, and 13 facilities [33%] provided a designated smoking area. Three of these 13 nursing homes with similar levels of care agreed to participate in study that was more comprehensive. The levels of carbon monoxide, carbon dioxide [CO2], respirable suspended particulate matter, nicotine, and solanesol were monitored at three locations within three nursing homes: a designated smoking room with an independent ventilation system, the adjacent hallway and outside the building. The concentrations of air contaminants, except CO2, inside the designated smoking rooms were significantly higher than those in the hallways or outside. The concentration of CO2 was similar in the smoking rooms and the hallways but significantly higher than the concentration outside. The levels of ambient air temperature or relative humidity within the three locations were not generally different. The results indicated that the designation of a smoking room with an independent ventilation system was effective in controlling the environmental tobacco smoke in these nursing homes

Determination of benzene, toluene and xylene [BTX] concentrations in air using HPLC developed method compared to gas chromatography

A new method for analysis of benzene, toluene, and xylene [BTX] using High Performance Liquid Chromatography-UV detection [HPLC-UV] is described and compared to the gas chromatography [GC] method. A charcoal adsorption tube connected to a small pump was used to obtain samples from an atmosphere chamber standard. Samples were extracted with methanol and analyzed by HPLC-UV. Chromatography was isocratic in a mobile phase consisting of water-methanol [30-70]. The flow rate was set at 1 ml/min. The analyses were completely separated and were quantified using both methods. The results demonstrated no statistically significant differences between BTX concentrations between the two analytical methods with a correlation coefficient of 0.98-0.99. The GC method provided higher sensitivity than HPLC, but the HPLC determination of BTX were applicable to real samples because its sensivity was lower than the thershold limit recommended by the American Conference of Governmental Industrial Hygienist [ACGIH] for an 8-hour workday

Synthesis of molecularly imprinted polymer as a solid phase sorbent for pesticide dursban

This study describes the synthesis of molecularly imprinted polymers [MIPs] by using an Anti-ChE OPs, namely dursban, as a template. Non-covalent bulk polymerization was successfully applied to synthesis different imprinted and non-imprinted polymers with MAA, MMA, AA, and 4-vpy as monomer in selected porogens [chloroform, toluene, and acetonitrile]. In order to evaluate the template binding of the polymers, equilibrium binding experiments was carried out. High binding amount of imprinted polymers compared to non-imprinted polymer was due to effective imprinting or encoding of dursban template shape in the polymer matrixes. From this study, the dursban imprinted polymers prepared using acidic MAA as a functional monomer showed excellent molecular binding ability for dursban. This is because the hydrogen binding interaction between dursban and MAA may be formed between sulfur, oxygen, chlorine, and nitrogen groups of dursban and carboxyl group of MAA. The results shows the use of chloroform as porogen, with a poor hydrogen binding power, significantly affects the binding extend of the MIPs. MAA and chloroform were found to be the most suitable monomer and porogen for the preparation of appropriate dursban molecularly imprinted polymers. This study has shown the possibility of synthesizing and using molecularly imprinted polymers as sorbent for an Anti-ChE Ops