Application of biological monitoring for exposure assessment of 1.3 Butadiene

BACKGROUND

1, 3-Butadiene is an important industrial compound. Based on sufficient evidence of carcinogenicity in laboratory animals and humans, the International Agency for Research on Cancer, in 1999, classified 1, 3-Butadiene as a probable carcinogen to humans (group 2A). The potential for exposure to vehicle exhaust containing these chemical compounds is very noticeable in urban locations. Exposure to incomplete combustion of gasoline has been a long time concern in many occupational fields, including policemen, service stations, and the petroleum industry but in Iran has rarely been studied.

METHODS

This study designed to determine the exposure levels for traffic policemen and gas station workers during routine work shift, by biological monitoring. With this aim, 25 policemen engaged in traffic control, 25 gas station workers and 25 occupationally non-exposed persons were investigated. Spot urine samples were obtained prior to and at the end of the work shift from each subject. The urinary levels of selected urinary metabolites (MHBMA and DHBMA) were determined by using LC-MS/MS.

RESULTS

There were significant differences among the mean urinary concentrations of DHBMA in pre-shift samples of policemen, gas station workers and occupationally non-exposed persons. The mean urinary concentrations of DHBMA differed significantly among post-shift samples of policemen and gas station (ANOVA: p < 0.05 and Kruskal-Wallis test: p < 0.05).

CONCLUSIONS

There was a significant difference in DHBMA concentrations between job categories (p < 0.05 by ANOVA and Kruskal-Wallis test), and policemen and gas station workers were found to be probably the most exposed groups in this study.

Association Among Sources Exposure of Cadmium in the Adult Non-smoking General Population of Tehran

Acute and chronic exposure to cadmium can cause numerous health effects including poisoning, as well as, bone, liver, and kidney diseases. Cadmium competes with iron absorption in blood and can induce anemia. Cadmium body burden can be measured through urine and blood samples. Urine reflects chronic and blood indicates recent and cumulative exposures to cadmium. Dietary is considered as the main source of exposure to cadmium in non-smoking general population. The study was conducted to determine cadmium level in blood, urine, and in diet of 120 non-smoking adults in Tehran. Dietary components and consumption pattern of participants estimated by a food frequency questionnaire. Next, the correlation investigated between them. Moreover, serum ferritin measured as a marker of iron storage in blood to determine its association with cadmium. The prediction of cadmium fate in the body is determined by toxicokinetic models. This study tried to evaluate one of these models' validity which is developed to predict urinary cadmium from dietary. Afterwards, the predicted urinary compared with the measured urinary cadmium. The correlation coefficient between dietary and blood cadmium equaled 0.66 which was statically significant, but the correlation between dietary and urinary cadmium was minimal and not statically significant (p > 0.05). An inverse and negative correlation was found between serum ferritin and blood cadmium. The mean predicted urinary cadmium calculated by the model was 2.5-fold higher than the measured value in the total population. Results of the present study revealed that blood cadmium reflected mainly acute exposure. There was no correlation between chronic and acute exposures to cadmium. The low serum ferritin level increased cadmium amount in blood. Moreover, the mean predicted urinary cadmium by the model was greater than the measured value. It can because of characteristics of populations and type of dietary exposure. Thus, it is suggested that the model coefficients are determined in each society based on their characteristics.

Determining additional risk of carcinogenicity and non-carcinogenicity of heavy metals (lead and arsenic) in raw and as-consumed samples of imported rice in Tehran, Iran

Rice is considered the most main food in Iranian diet. Its chemical contamination with heavy metals can lead to adverse effects to human health. In the present study, 60 imported rice samples from 20 different brands were collected and examined in terms of lead and arsenic levels in Tehran. Besides, point estimation and uncertainty analysis were used to determine the additional risk of carcinogenicity and non-carcinogenicity in raw and as-consumed rice. The results showed that the means of lead and arsenic (mg/kg fresh weight) in raw sampled rice were 0.0352 ± 0.0398 and 0.106 ± 0.049, respectively, and they were 0.0226 ± 0.0360 and 0.0689 ± 0.046 in as-consumed rice, respectively. Additionally, lead and arsenic amounts were 5% and 15% higher than the value set by Institute of Standards and Industrial Research of Iran respectively, while assessment of the non-carcinogenicity risk of lead and arsenic in point estimation and uncertainty analysis showed the hazard quotient and hazard index values were less than 1 and in safe ranges in both raw and as-consumed rice and were not considered a threat to the public health. The additional risk of arsenic carcinogenicity in point estimation and uncertainty analysis in raw and as-consumed rice samples found higher than the 1E-06 EPA's acceptable level of risk. So, these results could be applicable and encourage researchers to perform more detailed studies with more samples for considering by food authorities.

Environmental exposure to endotoxin and its health outcomes: A systematic review

Exposure to endotoxin occurs environmentally and occupationally. There are several differences between them in terms of the variety and severity of health outcomes, possible exposed groups and type and route of exposure. Occupational exposures caused adverse health outcomes in almost all cases, but there is disparity in the incidence of significant health outcomes due to environmental exposure to endotoxin. This study has therefore endeavoured to investigate health outcomes from environmental exposure to endotoxin. A systematic review was conducted of three databases and non-occupational studies reporting the environmental concentration of endotoxin, and observed health outcomes in exposed groups were included in the review (n = 27). The studies showed that first exposure to endotoxin occurs in infancy by the inhalation route. Inhalation is the only exposure route that can induce inflammation as the main symptom of exposure to endotoxin. The studies included were conducted using four approaches: molecular immunology, measurement of lung volumes, clinical sensitisation test and diagnosis of asthmatic and respiratory symptoms such as wheezing. By the immunological approach, all the included studies reported that environmental exposure to endotoxin, especially at a younger age, has a protective effect on the incidence of asthma in adolescence. The main disparity observed was in studies using the approach of diagnosed asthma. Overall, however, they confirm the protective effect of exposure to endotoxin although, in the case of children with non-atopic asthma, the results could be different.

What do we know about exposure of Iranians to cadmium? Findings from a systematic review

Cadmium is an important environmental contaminant. High consumption of chemical fertilizers and industrial activities in recent decades has caused people to be worried about exposure to cadmium. There is no policy for environmental and biological monitoring of exposure to cadmium in the general population in Iran. This study was aimed to review cadmium content in consuming foods and biological samples in Iran, systematically. We developed a comprehensive search strategy and used it to search on Web of Science, Scopus, Science Direct, and Scientific Information Database until 28 December 2016. The totals of 285 articles were identified and finally 31 original papers were selected. Cadmium contamination was found in Iranian food groups such as rice, cereal and legumes, canned tuna fish, vegetables, fruit juice, and egg. This study showed that cadmium amount in 75% of the consumed rice samples (domestic and imported) was higher than the maximum limits approved by institute of standards and industrial research of Iran. Lettuce samples in Yazd were recorded the highest concentration of cadmium compared to other studies. In addition, high amount of cadmium was observed in the blood of the general population. Regarding the cadmium contamination in food and blood samples in Iran, policies must be adopted to reduce exposure to cadmium through different matrices as much as possible.

Health risk assessment to fluoride in drinking water of rural residents living in the Poldasht city, Northwest of Iran

This study analyzes the concentrations and health risks of fluoride in 112 drinking water samples collected from 28 villages of the Poldasht city, West Azerbaijan province in Iran. Results indicated that fluoride content in drinking water ranged from0.27 to 10.3mgL^-1 (average 1.70mgL^-1). The 57% of samples analyzed exceeded the limit set for fluoride in drinking water. Based on findings from health risk assessment this study, the highest fluoride exposure for different regions of Poldasht city was observed in young consumers, children and teenager's groups. Also, most of the rural residents suffered from fluoride contaminated drinking water. The calculated HQ value was > 1 for all groups of residents in Agh otlogh and Sari soo areas. Therefore, it is imperative to take measures to reduce fluoride concentration in drinking water and control of fluorosis. Action should be implemented to enhance monitoring of fluoride levels to avoid the potential risk to the population.

Assessment of indoor and outdoor particulate air pollution at an urban background site in Iran

The relationship between indoor and outdoor particulate air pollution was investigated at an urban background site on the Payambar Azam Campus of Mazandaran University of Medical Sciences in Sari, Northern Iran. The concentration of particulate matter sized with a diameter less than 1 μm (PM_1.0), 2.5 μm (PM_2.5), and 10 μm (PM₁₀) was evaluated at 5 outdoor and 12 indoor locations. Indoor sites included classrooms, corridors, and office sites in four university buildings. Outdoor PM concentrations were characterized at five locations around the university campus. Indoor and outdoor PM measurements (1-min resolution) were conducted in parallel during weekday mornings and afternoons. No difference found between indoor PM₁₀ (50.1 ± 32.1 μg/m³) and outdoor PM₁₀ concentrations (46.5 ± 26.0 μg/m³), indoor PM_2.5 (22.6 ± 17.4 μg/m³) and outdoor PM_2.5 concentration (22.2 ± 15.4 μg/m³), or indoor PM_1.0 (14.5 ± 13.4 μg/m³) and outdoor mean PM_1.0 concentrations (14.2 ± 12.3 μg/m³). Despite these similar concentrations, no correlations were found between outdoor and indoor PM levels. The present findings are not only of importance for the potential health effects of particulate air pollution on people who spend their daytime over a period of several hours in closed and confined spaces located at a university campus but also can inform regulatory about the improvement of indoor air quality, especially in developing countries.

Risk assessment of haloacetic acids in the water supply of Tehran, Iran

Disinfection by-products are compounds occurring in drinking water as a result of reactions between disinfectants and impurities in raw water, and their occurrence has been a public health concern for the last four decades. Haloacetic acids (HAAs) are one of the major by-products of chlorination. The concentration and variation of HAAs was monitored in 540 samples taken from tap water in six water and wastewater districts of Tehran, Iran. Seasonal variation indicated that natural organic matter and HAA levels were much higher in the spring and fall seasons. The concentrations of HAAs in drinking water samples varied with water sources. They were higher in drinking water obtained from surface water. In this study, the analysis method of human health risk assessment with regard to exposure to HAAs by drinking water in Tehran was based on the United States Environmental Protection Agency (USEPA) guideline. It was found from these studies that the risk to human health appears to be negligible.

Determination of aluminum and zinc in infusion tea cultivated in north of Iran

To determine aluminum and zinc levels in black tea cultivated in north of Iran, 105 black tea samples were collected from the tea growing regions of Guilan and Mazandaran provinces and were analyzed for Al and Zn concentration of tea infusion. Contents of all elements were analyzed three times separately by using an Inductively Coupled Plasma Atomic Emission Spectrometry (ICP - AES). The solubility of Al and Zn in infusions at 5, 15 and 60 min with boiling water showed that the mean level of Al in the third infusion was the highest (262.09 mg/kg) and in the first infusion was the lowest (169.40 mg/kg). The mean level of Zn in the third infusion was the highest (51.40 mg/kg) and in the second infusion was the lowest (48.33 mg/kg). The analysis of results also showed that the location factor influences the contents of these metals at different infusions.

Study on the TOC concentration in raw water and HAAs in Tehran's water treatment plant outlet

A sampling has been undertaken to investigate the variation of haloacetic acids formation and nature organic matter through 81 samples were collected from three water treatment plant and three major rivers of Tehran Iran. Changes in the total organic matter (TOC), ultraviolet absorbance (UV254), specific ultraviolet absorbance (SUVA) were measured in raw water samples. Haloacetic acids concentrations were monitored using a new static headspace GC-ECD method without a manual pre-concentration in three water treatment plants. The average concentration of TOC and HAAs in three rivers and three water treatment plants in spring, summer and fall, were 4, 2.41 and 4.03 mg/L and 48.75, 43.79 and 51.07 μg/L respectively. Seasonal variation indicated that HAAs levels were much higher in spring and fall.