Preliminary Risk assessment for Acrylamide and Peripheral Neuropathy.

Acrylamide (ACM) is a high-volume industrial chemical with diverse uses in manufacturing, construction and laboratory research. ACM is a well-established neurotoxic agent causing peripheral neuropathy with impairment in the arms and legs of exposed workers, most thoroughly studied in Swedish tunnel workers exposed to ACM grouting. A quantitative risk assessment was performed to assess ACM risk to workers. Using data from a published paper investigating peripheral neuropathies in Chinese chemical workers, estimates of exposure response for vibration perception threshold and nerve conduction velocities were calculated, based on hemoglobin adducts and air concentrations as exposure metrics. The benchmark dose procedure was applied in order to calculate excess risks of impairment, defined as adverse performance exceeding the 95th percentile in unexposed populations, at various concentrations of airborne ACM exposure. Under the assumptions in this risk assessment, after three years of inhalation exposure at 0.3 mg/m3, the excess attributable impairment manifest in vibration perception and nerve conduction velocity is estimated to occur in 1-2% of workers. For 10 years at 0.3 mg/m3 ACM inhalation (equivalent to 3 years at 1.0 mg/m3) the excess prevalence of impairment would be 2-14% of workers, assuming the effect continues to accrue linearly in time. Using published data, the risks of impairment from peripheral neuropathy attributable to exclusively airborne ACM exposure can be predicted for exposure periods less than 10 years. The risks associated with dermal and airborne ACM exposures can be estimated by characterizing working process environments using ACM Hb-adduct levels and possibly monitored with urinary biomarkers.

In vivo assessment of the protection conferred by ß-glucans from Pleurotus ostreatus against the harmful effects of acrylamide intake (Part I).

INTRODUCTION: Introduction: acrylamide is formed in food through Maillard's reaction during thermal processing, and has been shown to be neurotoxic in humans, and a possible carcinogen. Studies have shown that ß-glucans from Pleurotus ostreatus have diverse biological properties such as antioxidant and anticancer activities. Objective: the aim of this work was to evaluate the protective effect of ß-glucans from Pleurotus ostreatus against the harmful effects of acrylamide consumption in mice. Methods: ß-glucans were obtained by alkaline-acid hydrolysis of Pleurotus ostreatus, and the content was characterized by liquid chromatography. To evaluate the effect of ß-glucans on the expression of glutathione, Balb/c mice were used, and 4 test groups were established. All groups were fed normally, and the groups treated with acrylamide were administered the compound intragastrically at a concentration of 50 g/mL; ß-glucans were administered at a concentration of 50 g/mL. Results: mice exposed to acrylamide showed a marked variation in the activity of glutathione enzymes in the liver. Significant differences (p < 0.05) were only found in the expression of glutathione transferase, which was increased almost 3 times in the group treated with ß-glucans as compared with the control group, and 1.5 times as compared with the group treated with acrylamide. Conclusions: the results show that ß-glucans could act by increasing the activity of enzymes involved in xenobiotic detoxification, thus protecting the biological system against the harmful effects caused by acrylamide intake.

INTRODUCCIÓN: Introducción: la acrilamida se forma en los alimentos a través de la reacción de Maillard durante el proceso térmico, y ha demostrado ser neurotóxica en humanos y un posible carcinógeno. Algunos estudios han demostrado que los ß-glucanos de Pleurotus ostreatus tienen diversas propiedades biológicas, como actividades antioxidantes y anticancerígenas. Objetivo: el objetivo de este trabajo fue evaluar el efecto protector de los ß-glucanos de Pleurotus ostreatus contra los efectos nocivos por consumo de acrilamida en ratones (prueba in vivo). Métodos: los ß-glucanos se obtuvieron por hidrólisis ácido-alcalina de Pleurotus ostreatus y su contenido se caracterizó por cromatografía líquida. La oxidación de los lípidos se evaluó mediante el método de TBARS, y para evaluar el efecto de los ß-glucanos en la expresión de glutatión se usaron ratones Balb/c, y se establecieron 4 grupos de prueba. Todos los grupos fueron alimentados normalmente; a lo grupos tratados con acrilamida, esta se les administró intragástricamente en una concentración de 50 µg/ml, y los ß-glucanos en una concentración de 50 µg/ml. Resultados: en el presente trabajo, los ratones expuestos a acrilamida mostraron una marcada variación en la actividad de las enzimas de glutatión determinadas en el hígado. Solo se encontraron diferencias significativas (p < 0,05) en la expresión de glutatión-transferasa, que aumentó casi 3 veces en el grupo tratado con ß-glucano en comparación con el grupo de control, y 1,5 veces con respecto al grupo tratado con acrilamida. Conclusiones: los resultados muestran que los ß-glucanos podrían actuar como agentes antioxidantes que protegen el hígado contra el estrés oxidativo causado por la ingesta de acrilamida.

Dietary acrylamide exposure from traditional food products in Lesser Poland and associated risk assessment.

INTRODUCTION AND OBJECTIVE: Acrylamide (AA) is a carcinogenic and genotoxic food contaminant occurring in carbohydrate-rich foods produced at high cooking temperatures. The aim of the study was to determine the importance of AA exposure with respect to traditional food and to assess the associated risks. MATERIAL AND METHODS: 165 food samples were collected from local markets in Lesser Poland. The participants enrolled in the study were 500 residents: (males - 179, females - 321) who had purchased food from local markets. Exposure of the participants to AA was assessed by combining the analytical AA results with data on the individual consumption of traditional foods. Risk assessment of AA exposure from traditional foods was estimated and the margin of exposure (MOE) values were calculated. RESULTS: The highest mean AA level was measured in pretzels (92 µg kg -1), followed by bagels (74.81 µg kg-1) and pork paté (59.56 µg kg-1). The average and 95th percentile values of AA exposure were 0.213 and 0.458 [µg kg-1 body weight (BW) day-1]. The calculated values of MOE for the average [798 and 2,019 for both benchmark dose lower confidence limit (BMDL) 0.17 and 0.43 mg kg-1 BW day-1] and 95th percentile AA exposure values (371 and 939 for both BMDL 0.17and 0.43 mg kg -1 BW day-1) suggest that there is a health concern with respect to adult residents. CONCLUSIONS: The results of the study confirm the general recommendation to the consumers, especially certain population groups, to eat a balanced healthy diet and to limit the amount of baked cereal products and fried products.

Health risk assessment of acrylamide in bread in Iran using LC-MS/MS.

Acrylamide is a chemical, often present in bread, legally classified as carcinogen, mutagen and reproductive toxicant. Since bread is consumed both world-wide and in Iran, determination of acrylamide in different types of breads is of high interest. In the present study, acrylamide was monitored in 56 Sangak and 30 industrial bread samples collected from Tehran and Shiraz, using LC-MS/MS (LOQ = 1 ng/g). In addition, the noncarcinogenic risk (target hazard quotient-THQ) and carcinogenic risk (incremental lifetime cancer risk-ILCR) due to ingestion of acrylamide through bread consumption in children and adults were assessed. Acrylamide was detected in more than 90% of the samples tested. The average daily intake of acrylamide in Iran based on exclusive consumption of Sangak bread, was estimated at 145 ng/kg bw/day. Based on the THQ for bread acrylamide in adults and children, the decreasing risk order was: Shiraz semi-industrial Sangak, Shiraz traditional Sangak, Tehran traditional Sangak, Tehran industrial bread. The ILCR of bread acrylamide calculated for adults and children was higher than the permissible lifetime carcinogenic risk value established by USEPA (1.00E-5). Results show that bread is a major source of acrylamide intake by people in Iran and all consumers regardless of age could be at elevated carcinogenic risk.

Human exposure to selected animal neurocarcinogens: a biomarker-based assessment and implications for brain tumor epidemiology.

This review is based on the proceedings from the Second Lebow Conference, held in Chicago in 2007. The conference concentrated on developing a framework for innovative studies in the epidemiology of environmental exposures, focusing specifically on the potential relationship with brain tumors. Researchers with different perspectives, including toxicology, pharmacokinetics, and epidemiological exposure assessment, exchanged information and ideas on the use of biomarkers of exposure in molecular epidemiology studies and summarized the current knowledge on methods and approaches for biomarker-based exposure assessment. This report presents the state of science regarding biomarker-based exposure assessment of the four most common neurocarcinogens: acrylamide, 1,3-butadiene, N-nitroso compounds, and polycyclic aromatic hydrocarbons. Importantly, these chemicals are also carcinogenic in other organs; therefore, this discussion is useful for environmental epidemiologists studying all cancer types.

Analysis of urinary N-acetyl-S-(propionamide)-cysteine as a biomarker for the assessment of acrylamide exposure in smokers.

Acrylamide, classified by the IARC as a probable human carcinogen (Group 2A), is present in cigarette mainstream smoke and also some high-temperature-processed foods, thus smokers and consumers of certain foods are at risk of acrylamide exposure. The objectives of this study were to analyze N-acetyl-S-(propionamide)-cysteine (NASPC), an acrylamide metabolite, in the urine of smokers and nonsmokers, and to investigate the association between acrylamide exposure and urinary NASPC levels in smokers and nonsmokers in order to validate NASPC as a biomarker for the assessment of acrylamide exposure. Urine samples from 63 male military officers were collected as well as background personal information and smoking habits using questionnaires. Acrylamide exposure from tobacco smoke was represented by self-reported daily cigarette consumption and urinary cotinine levels. NASPC and cotinine were analyzed using our newly developed liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) methods. Our results reveal a statistically significant linear relationship between urinary NASPC and cotinine levels for smokers (Spearman correlation coefficient r=0.402, P=0.028), but insignificantly so for nonsmokers. These results verify our suggestion that urinary NASPC could serve as a sensitive, specific, noninvasive, and easily accessible biomarker for low-dose acrylamide exposure as also exposure to carcinogens in tobacco smoke. Routine monitoring of urinary NASPC could be used to assess human exposures to acrylamide in the living environment and the workplace.

Risk assessment of dietary acrylamide intake in Flemish adolescents.

Acrylamide has recently been found in a range of heat treated food items. As it is a neurotoxic agent and a probable, human carcinogen (IARC 2A), human exposure to this chemical might constitute an important public health issue. The purpose of the study was to estimate the acrylamide intake in Flemish adolescents (based on 7-day food record) and to evaluate the possible health risks due to the exposure. The Belgian Federal Agency for the Safety of the Food Chain collected 150 food items from different supermarkets and restaurants to analyse the acrylamide level. The limit of quantitation was 30 microg acrylamide/kg foodstuffs. Exposure modelling was based on Monte Carlo simulations. The estimated dietary intake of acrylamide per person given as the 5th, 50th and 95th percentile were 0.19, 0.51 and 1.09 mircog/kg bw/d. Bread, despite its low acrylamide content, is relevant as a source of acrylamide exposure at the lower percentiles. At higher percentiles the contribution of French fries and crisps is more important. It must be emphasised that the exposure assessment has several limitations. Risk of neurotoxicity seems negligible. The relevance of current intake levels in terms of cancer risk remains a subject of debate.

Estimates of lifetime-absorbed daily doses from the use of personal-care products containing polyacrylamide: a Monte Carlo analysis.

Estimates of the lifetime-absorbed daily dose (LADD) of acrylamide resulting from use of representative personal-care products containing polyacrylamides have been developed. All of the parameters that determine the amount of acrylamide absorbed by an individual vary from one individual to another. Moreover, for some parameters there is uncertainty as to which is the correct or representative value from a range of values. Consequently, the parameters used in the estimation of the LADD of acrylamide from usage of a particular product type (e.g., deodorant, makeup, etc.) were represented by distributions evaluated using Monte Carlo analyses.((1-4)) From these data, distributions of values for key parameters, such as the amount of acrylamide in polyacrylamide, absorption fraction, etc., were defined and used to provide a distribution of LADDs for each personal-care product. The estimated total acrylamide LADD (across all products) for males and females at the median, mean, and 95th percentile of the distribution of individual LADD values were 4.7 x 10(-8), 2.3 x 10(-7), and 7.3 x 10(-7) mg/kg/day for females and 3.6 x 10(-8), 1.7 x 10(-7), and 5.4 x 10(-7) mg/kg/day for males. The ratio of the LADDs to risk-specific dose corresponding to a target risk level of 1 x 10(-5), the acceptable risk level for this investigation, derived using approaches typically used by the FDA, the USEPA, and proposed for use by the European Union (EU) were also calculated. All ratios were well below 1, indicating that all the extra lifetime cancer risk from the use of polyacrylamide-containing personal-care products, in the manner assumed in this assessment, are well below acceptable levels. Even if it were assumed that an individual used all of the products together, the estimated LADD would still provide a dose that was well below the acceptable risk levels.