Main Source Of Human Exposure Research Articles

New Sight of Renal Toxicity Caused by UV-Aged Polystyrene Nanoplastics: Induced Ferroptosis via Adsorption of Transferrin.

Secondary nanoplastics (NPs) caused by degradation and aging due to environmental factors are the main source of human exposure, and alterations in the physicochemical and biological properties of NPs induced by environmental factors cannot be overlooked. In this study, pristine polystyrene (PS) NPs to obtain ultraviolet (UV)-aged PS NPs (aPS NPs) as secondary NPs is artificially aged. In a mouse oral exposure model, the nephrotoxicity of PS NPs and aPS NPs is compared, and the results showed that aPS NPs exposure induced more serious destruction of kidney tissue structure and function, along with characteristic changes in ferroptosis. Subsequent in vitro experiments revealed that aPS NPs-induced cell death in human renal tubular epithelial cells involved ferroptosis, which is supported by the use of ferrostatin-1, a ferroptosis inhibitor. Notably, it is discovered that aPS NPs can enhance the binding of serum transferrin (TF) to its receptor on the cell membrane by forming an aPS-TF complex, leading to an increase in intracellular Fe2+ and then exacerbation of oxidative stress and lipid peroxidation, which render cells more sensitive to ferroptosis. These findings indicated that UV irradiation can alter the physicochemical and biological properties of NPs, enhancing their kidney biological toxicity risk by inducing ferroptosis.

Evaluation of the degree of contamination of breast milk by organochlorine pesticides in the Lower Amazon region: a preliminary study

The main source of human exposure to organochlorines is through food, especially food with a high fat content, such as breast milk, which is critical for child hood development. Therefore, it is important to analyze milk and other biological matrices for organochlorine pesticides (OCPs), and then determine the source of the OCP contamination. The objective of this study was to evaluate the degree of contamination by OCP residues and their metabolites in breast milk samples from the municipalities of Mojuí dos Campos and Belterra-Pará, Brazil. The OCPs analyzed were dichlorodiphenyltrichloroethane (DDT) and its metabolites (o,p'-DDT, p,p'-DDT, o,p'-DDE, p,p'-DDE, o,p'-DDD, and p,p'-DDD), aldrin, endrin, dieldrin, hexachlorocyclohexanes (α-HCH, β-HCH, lindane (γ-HCH), and δ-HCH­­), endosulfan α and β, endosulfan sulfate, heptachlor, and heptachlor epoxide. These substances were analyzed in 22 breast milk samples using gas chromatography with an electron capture detector (GC-ECD). Seven were contaminated with p,p'-DDT and/or p,p'-DDE. The mean p,p'-DDT and p,p’-DDE content in the contaminated samples was 0.0022 and 0.0152 mg·kg-1 of milk, respectively. This contamination may have been due to the inadequate application of DDT until the end of the 1990s for the control of tropical diseases, including malaria. Despite being a preliminary study, the number of contaminated samples was significant, which suggests the need to expand this study to other environmental and biological matrices.

Risk assessment of food contact materials.

Bisphenol A (BPA) is authorised for use as a chemical compound for the production of plastic food contact materials (FCMs) under Regulation (EU) No 10/2011. But according to requirements of the Regulation (EU) No 2018/213, BPA has been banned in the manufacture of polycarbonate drinking cups or feeding bottles intended for infants and young children. Food has been identified as the main source of human exposure to BPA, followed by dermal absorption, air and dust inhalation, revealing ubiquitous and continuous contact with BPA. Considering that BPA is able to enter the food chain through the migration from food packaging into foodstuffs, assessment of dietary exposure is necessary for accurate estimations and identification of potential exposure from food sources. In 2015, EFSA set a temporary tolerable daily intake (TDI) for BPA of 4 μg/kg body weight (bw) per day and concluded that no health concern from BPA exposure for any age group was to be expected. In 2023, EFSA has re-evaluated BPA safety and the new TDI was reduced by a factor of 20,000 resulting in a TDI of 0.2 ng/kg bw per day. In this case, the CEP Panel concluded that there is a health concern from dietary exposure to BPA. Amongst others, the BfR identified several points of criticism which, in the opinion of the BfR, call into question the risk assessment carried out by EFSA. The BfR derived a TDI of 200 ng/kg bw per day and suggests taking this into account for risk assessment. In the proposed EU-FORA programme, the fellow had the opportunity to gain experience in the exposure assessment and then integrate the data together with the BfR hazard assessment to perform a comprehensive risk assessment. As second objective of the work programme, the fellow was in charge of performing a toxicokinetic analysis in an attempt to correlate external exposure with urinary BPA levels.

Development of a Pre-Diagnosis Procedure for the Evaluation of Indoor Radon Potential in Buildings

Indoor radon accumulation is considered the main source of human exposure to ionizing radiation. Depending on the average radon level, indoor long-term exposure can significantly increase the risk of lung cancer onset. The publication of international regulations on the protection of human health the exposure of ionizing radiation, defining threshold values over whom health consequences for occupants could be expected, led to the control and testing of radon levels in workplaces and premises using multiple techniques and approaches. In particular, since the main source of radon is soil, many efforts have been done for the redaction of maps of the geogenic potential risk, as well as the definition of proper measurement standards and techniques for indoor monitoring. Radon maps, based on geology and measurements of radon and/ or the natural radioactive content in the soil, constitute an evaluable tool for decision-making authorities in radon policies giving the possibility to characterize areas for radon risk where indoor radon measurements are not available. But, of course, they are not completely descriptive of the potential risk, so indoor monitoring in buildings is also required. The correct design of an indoor monitoring campaign is a crucial topic.. Scientific literature has largely demonstrated that many site-specific features influence the accumulation process, as well as most building materials represent a significant source, after the soil. The preliminary complete investigation in buildings should be properly defined since radiation safety in a situation of radon exposure completely ensured during the building's construction and maintenance phases as well as during the selling/rental ones. So, the aim of this work is to put the basis for the development of a pre-diagnosis procedure as a tool for the screening of buildings susceptible to high indoor radon activity concentrations. The work represents a very early stage of implementation of a qualitative method for the design of a measurement campaign for the indoor radon assessment. A pre-evaluation selection of the variables that play a leading role in the accumulation process is presented. A prior survey, based on evidence in scientific literature, was done to identify all relevant characteristics that most affect indoor radon levels, mainly concerning local geology, building features, ventilation, and occupancy factors. The selected parameters, classified into levels according to defined indicators and then combined, allow a more refined sample selection for measurements campaign in the indoor radon assessment process. Future development will be oriented to the validation of case studies and the implementation of the procedure in a software environment which will be the first tool available to systematize and regulate the radon monitoring process for short-term decision-making.

Evaluation of the oral bioaccessibility of legacy and emerging brominated flame retardants in indoor dust.

Indoor dust is the main source of human exposure to brominated flame retardants (BFRs). In this study, in vitro colon-extended physiologically-based extraction test (CE-PBET) with Tenax as a sorptive sink was applied to evaluate the oral bioaccessibility of twenty-two polybrominated diphenyl ethers (PBDEs) and seven novel BFRs (NBFRs) via indoor dust ingestion. The mean bioaccessibilities of two NBFRs pentabromotoluene (PBT) and 1,2-Bis(2,4,6-tribromophenoxy) ethane (BTBPE) were first proposed, reaching 36.0% and 26.7%, respectively. In order to maintain homeostasis of the gastrointestinal tract, 0.4g Tenax was added in CE-PEBT, which increased BFRs bioaccessibility by up to a factor of 1.4-1.9. The highest bioaccessibility of legacy PBDEs was tri-BDEs (73.3%), while 2-ethylhexyl-tetrabromo-benzoate (EHTBB), one of penta-BDE alternatives, showed the highest (62.2%) among NBFRs. The influence of food nutrients, liquid to solid (L/S) ratio, and octanol-water partition coefficient (Kow) on bioaccessibility was assessed. The oral bioaccessibility of BFRs increased with existence of protein or carbohydrate while lipid did the opposite. The bioaccessibilities of PBDEs and NBFRs were relatively higher with 200:1 L/S ratio. PBDEs bioaccessibility generally decreased with increasing LogKow. No significant correlation was observed between NBFRs bioaccessibility and LogKow. This study comprehensively evaluated the bioaccessibilities of legacy and emerging BFRs via dust ingestion using Tenax-assisted CE-PBET, and highlighted the significance to fully consider potential influencing factors on BFRs bioaccessibility in further human exposure estimation.

Analysis of the Mercury Content in Fish for Human Consumption in Poland.

Mercury (Hg) is a metal with toxic effects on the environment, including living organisms. Organic Hg derivatives readily penetrate biological membranes and pose a particular health risk. Food of aquatic origin is the main source of human exposure to methylmercury (MeHg). In Poland, the consumption of fishery and aquaculture products has been gradually increasing. The aim of this study was to determine the content of Hg in fish intended for human consumption and purchased in Poland. The total Hg content of the edible parts of different species of marine and freshwater fish was analysed. The range of Hg content in all fish was 0.004-0.827 mg/kg, with an arithmetic mean of 0.084 mg/kg. The concentration of Hg in marine fish (0.100 mg/kg) was higher than in freshwater fish (0.063 mg/kg). The highest concentration of Hg was found in tuna. The Estimated Hazard Quotient (EHQ) calculated for the tuna samples analysed was >1. This may represent a potential health risk for consumers. The consumption of the other fish analysed was considered safe on the basis of the EHQ. The Hg content of the analysed fish samples did not exceed the current limits for food.

Determination of polybrominated diphenyl ethers in shrimp and animal origin oils in Medellín, Colombia

ABSTRACT Polybrominated diphenyl ethers (PBDEs) are synthetic organic compounds that have been used as brominated flame retardants. They are persistent in the environment, can bioaccumulate in fatty tissues, biomagnify through the food chain, and have adverse health effects on humans and wildlife. The main source of human exposure to PBDEs is the ingestion of contaminated food. Therefore, in this study the concentration of BDE-28, BDE-47, BDE-77, BDE-99, BDE-100, BDE-126, BDE-139, BDE-153, BDE-154, and BDE-183 was determined by gas chromatography coupled to mass spectrometry in shrimps and animal origin oils commercialised and consumed in Medellín, Colombia. All samples of shrimps and animal origin oils analysed had values below 0.0050 ng·g−1 for all the PBDEs studied, with the exception of one shrimp sample in which a concentration of 0.012 ± 0.0056 ng·g−1 of BDE-100 was quantified. The results suggest that shrimps and animal origin oils are not a significant source of exposure to PBDEs of the population of the city. However, it is important to continue analysing PBDEs in foods, including foods other than those evaluated in this investigation, in order to guarantee the innocuity and safety of the food consumed by the population.

Survival of Campylobacter jejuni in frozen chicken meat and risks associated with handling contaminated chicken in the kitchen

Most Campylobacter infections in humans are sporadic cases, often connected to private households. Chicken meat is believed to be the main source of human exposure to Campylobacter and there are significant risks of cross-contamination when handling Campylobacter -contaminated chicken in the kitchen. One post-harvest preventive measure to reduce Campylobacter concentrations on chicken meat is freezing. This study examined survival of different sequence types of C. jejuni during freezing and risk factors during handling of C. jejuni –contaminated chicken meat in the kitchen. Chicken fillets were artificially contaminated before freezing with two different sequence types of C. jejuni (ST-257 and ST-918), at concentrations in the meat of 4.1 log 10 CFU/g (low) and 5.3 log 10 CFU/g (high). Risk factors in the kitchen were assessed by swabbing gloves before and after washing, to simulate hands before and after washing. Utensils such as scissors and forceps used for cutting were also sampled, while a cutting board was sampled twice to simulate before and after wiping. The greatest decrease in Campylobacter concentrations in the freezer occurred in the first four days and the decrease then flattened off. After 49 days in the freezer, concentrations on meat contaminated with high and low levels of ST-257 decreased by 2.0 log 10 CFU/g and 1.5 log 10 CFU/g, respectively, while concentrations on chicken meat contaminated with a high and low level of ST-918 decreased by 1.0 log 10 CFU/g and 0.7 log 10 CFU/g, respectively. Campylobacter was isolated from all simulated environmental samples. The highest load in the environment of both sequence types was unwashed gloves and the first sampling of the unwiped cutting board. Transfer from gloves and the cutting board was lower after washing/wiping, but high concentrations (≥2 log 10 CFU/mL rinse fluid) of Campylobacter persisted for all samples contaminated with ST-918 and for 18 of 20 samples contaminated with ST-257. In conclusion, there are differences between Campylobacter sequence types in their ability to withstand freezing stress and Campylobacter remaining on hands after washing and on cutting boards after wiping is a likely source of cross-contamination in the kitchen. Highlights • High levels of C. jejuni remain on hands and cutting board after cleaning. • Ability to withstand stress such as freezing differ between C. jejuni sequence types. • Hands and cutting boards have the highest load of C. jejuni in kitchen. • The greatest decrease in C. jejuni occurs in the first four days of freezing. • The C. jejuni reduction during freezing is lower for low-contaminated meat.

Rapid determination of PCDDs, PCDFs and DL-PCBs in foods, feeding stuffs and vegetable oils using new modified acid silica

Polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls are persistent organic pollutants (POPs), which in recent years received huge attention due to their extreme stability, high potential toxicity and bioaccumulation in food chains. The main source of human exposure to these compounds is discovered in foods of animal origin, especially foods rich in fat. The target of the present study was to set up an analytical method for the determination of PCDDs/PCDFs and DL-PCB in vegetable oils, sunflower meals, sunflower seeds, rapeseeds and milk powder. The first step consisted of a semi-automatic Soxhlet extraction for 3 hours, by using a mixture of Hexane: Acetone – 80:20, followed by acid digestion with 55% acid silica and filtration. After concentration, the extract is purified on a multilayer column (silica gel, silica-KOH, silica-H2SO4 anhydrous Na2SO4) followed by an alumina column separation in two fractions (first fraction containing PCDDs/PCDFs and second containing only PCBs). The purified extract was then analyzed by GC/MS/MS. The newly developed approach in our lab was capable to reduce the overall time of sample preparation to seven hours/ per sample. Since the method shows good mean recoveries for all labeled congeners spiked in the samples (for PCDDs/PCDFs – 80% - 110%, for DL-PCBs – 70% - 85%), we assumed the absence of overestimation or underestimation in the analyzed samples.

Application of In Vitro Models for Studying the Mechanisms Underlying the Obesogenic Action of Endocrine-Disrupting Chemicals (EDCs) as Food Contaminants-A Review.

Obesogenic endocrine-disrupting chemicals (EDCs) belong to the group of environmental contaminants, which can adversely affect human health. A growing body of evidence supports that chronic exposure to EDCs can contribute to a rapid increase in obesity among adults and children, especially in wealthy industrialized countries with a high production of widely used industrial chemicals such as plasticizers (bisphenols and phthalates), parabens, flame retardants, and pesticides. The main source of human exposure to obesogenic EDCs is through diet, particularly with the consumption of contaminated food such as meat, fish, fruit, vegetables, milk, and dairy products. EDCs can promote obesity by stimulating adipo- and lipogenesis of target cells such as adipocytes and hepatocytes, disrupting glucose metabolism and insulin secretion, and impacting hormonal appetite/satiety regulation. In vitro models still play an essential role in investigating potential environmental obesogens. The review aimed to provide information on currently available two-dimensional (2D) in vitro animal and human cell models applied for studying the mechanisms of obesogenic action of various industrial chemicals such as food contaminants. The advantages and limitations of in vitro models representing the crucial endocrine tissue (adipose tissue) and organs (liver and pancreas) involved in the etiology of obesity and metabolic diseases, which are applied to evaluate the effects of obesogenic EDCs and their disruption activity, were thoroughly and critically discussed.

MAIN SOURCES OF IONIZING RADIATION AND ITS IMPACT ON THE POPULATION

All sources of ionizing radiation (IR) of human exposure are divided into natural and industrial. Natural sources of radiation are the main sources of human exposure. They include cosmic rays and radiation from natural radionuclides contained in the Earth's crust and atmosphere. Among radionuclides of natural origin, potassium-40 and radionuclides arising from the decay of natural radioactive uranium-238 and thorium-232 are the most important. Potassium, uranium, and thorium present in the earth's crust, when disintegrating, become sources of radiation and form the background external radiation of a person, and entering the body with air, water, and food - internal background radiation. The situation in Ukraine is typical for most countries of the world, although the levels of population exposure from natural sources are somewhat higher than the world average. Industrial sources include sources of both natural origin and those created by man, if they are purposefully used in industrial, scientific, medical and other spheres of human activity with the aim of obtaining a certain benefit. Human exposure to industrial sources can occur in production conditions (professional exposure of workers) and in the living environment. Under normal operating conditions, artificial radiation sources are fully controllable, and exposure from them is predictable. Among all industrial sources of radiation of the planet's population, X-ray diagnostic procedures rank first in terms of dose. A special place is occupied by the exposure of the population and personnel as a result of radiation accidents. Dozens of radiation accidents occur every year in the world, accompanied by the exposure of a small number of people. In some cases, individual radiation doses exceeded several Sieverts and even led to the death of people. The worst radiation accident in terms of the number of people exposed to accidental radiation is Chernobyl. The levels of exposure of a significant part of the population of Ukraine by man-made and enhanced sources of natural origin are determined by certain geological characteristics of the territories. Ensuring radiation safety and anti-radiation protection should be a priority when using sources of ionizing radiation in practice.

Arsenic speciation in freshwater fish: challenges and research needs.

Food and water are the main sources of human exposure to arsenic. It is important to determine arsenic species in food because the toxicities of arsenic vary greatly with its chemical speciation. Extensive research has focused on high concentrations of arsenic species in marine organisms. The concentrations of arsenic species in freshwater fish are much lower, and their determination presents analytical challenges. In this review, we summarize the current state of knowledge on arsenic speciation in freshwater fish and discuss challenges and research needs. Fish samples are typically homogenized, and arsenic species are extracted using water/methanol with the assistance of sonication and enzyme treatment. Arsenic species in the extracts are commonly separated using high-performance liquid chromatography (HPLC) and detected using inductively coupled plasma mass spectrometry (ICPMS). Electrospray ionization tandem mass spectrometry, used in combination with HPLC and ICPMS, provides complementary information for the identification and characterization of arsenic species. The methods and perspectives discussed in this review, covering sample preparation, chromatography separation, and mass spectrometry detection, are directed to arsenic speciation in freshwater fish and applicable to studies of other food items. Despite progress made in arsenic speciation analysis, a large fraction of the total arsenic in freshwater fish remains unidentified. It is challenging to identify and quantify arsenic species present in complex sample matrices at very low concentrations. Further research is needed to improve the extraction efficiency, chromatographic resolution, detection sensitivity, and characterization capability.

Dioxin transfer simulation from feed to animal tissues and risk assessment

Dioxins might be introduced into the food chain through a direct or an indirect pathway. The main source of human exposure to dioxins is food of animal origin, whereas feeds are the main route of exposure of farmed animals to dioxins and polychlorinated biphenyls. The aim of the study was to simulate dioxin passage from feed to tissues on farm animals using transfer models, and, in addition, to assess the risk to consumers of food of animal origin. From over 700 feed samples analyzed over the course of 9 years (2013–2021), those exceeding the maximum permissible levels set down in Commission Regulation No 277/2012/EU were selected. These samples being derived from real cases of dioxin contamination made it possible to present the most realistic picture of the effects these feed materials could have had if they had entered the food chain. Three species of animals were selected (laying hens, dairy cattle and slaughter pigs), for which feed materials with dioxin contents exceeding the maximum permissible level were selected in accordance with the nutritional recommendations. The calculated PCDD/PCDF concentrations in chicken eggs, cow's milk and pork were above the maximum permissible level in most cases.

Health risks of environmental exposure to microplastics

Plastics are materials widely used in all sectors. The subject of interest in recent years has become so-called microplastics, whose composition and structure are causing new environmental hazards. The presence and accumulation of microplastics in the environment threaten the ecological balance, the water environment, food sustainability and safety, and ultimately human health. Human exposure to microplastics is primarily through the oral route, so the main source of human exposure to microplastics is diet. Despite many studies focusing on microplastic contamination in seafood, fish, and shellfish, estimating total human exposure to microplastics via the oral route is difficult, due to the lack of research on other foods in this area. The risks to human health from inhaling microplastics remain unclear. According to the WHO, there is no reliable evidence of the harmful effects of microplastic on the human body, but the phenomenon requires further research. Likely health effects of human exposure to microplastic include respiratory and gastrointestinal effects, oxidative stress, and cancer. There is a need to raise public awareness about environmental exposure to microplastics and effective waste management.

Monitoring survey of nitrate content in beetroot, radish and cabbage in Poland.

Nitrates, compounds commonly occurring in nature, are present for example in vegetables, where they accumulate and become their contaminants. It is estimated that approximately 70-90% of nitrates intake comes from vegetables, which are therefore the main source of human exposure to these compounds through dietary intake. The European Union legislation limits nitrates as contaminants to three leafy vegetables, i.e. lettuce, spinach and rucola. The EU Member States are obliged to monitor nitrate levels in vegetables which may contain significant levels of these compounds. Objective. To present the results of monitoring surveys on nitrate levels in radish and beetroot as well as in cabbage carried out in Poland between 2012 and 2019. A total of 966 vegetable samples were tested. Chemical analyses were carried out in accredited laboratories of the State Sanitary Inspection. Analyses were performed by spectrophotometric methods using nitrate reduction on cadmium columns or by HPLC. The median nitrate content in beetroot was 1,260.0 mg NO- 3 /kg, whilst at the 95th percentile level - 3,222.2 mg NO-3 /kg. The levels of nitrates in beetroot preserves were lower: 1,030.3 mg NO-3 /kg (median) and 2337,2 mg NO-3 /kg (95th percentile). The median content of nitrates in radish and cabbage was 1,337.0 mg NO-3 /kg and 369,0 mg NO-3 /kg respectively, while at the 95th percentile the content of these compounds was found to be 3,381.5 mg NO-3 /kg and 1545,8 mg NO-3 /kg, respectively. The nitrate content in radish and cabbage does not pose a risk to the health of consumers, whilst the consumption of beetroot containing significant amounts of the above mentioned compounds may result in exceeding the ADI especially for young children.

Speciation and accumulation pattern of heavy metals from soil to rice at different growth stages in farmland of southwestern China.

Paddy rice, one of the most important food crops in Southeast Asia, is considered a main source of human exposure to heavy metal contamination because it efficiently accumulates heavy metals. In the present study, of Japonica rice grains, straw, roots, leaves, and husks and rhizosphere paddy soils (0-20cm and 20-40cm depth) were collected from Zunyi in northern Guizhou Province, China. The forms of heavy metals, including Cr, Cd, Pb, Cu, and Zn, in the two soil profiles were investigated using Tessier's five-stage sequential extraction procedure. There was no heavy metal pollution in the study area based on the evaluation of the geo-accumulation index and the potential ecological risk index. Accumulation varied from one area to another, and the highest metal accumulation was found in the order of root > stems > leaves. The bioaccumulation factor (BCF) results revealed that during the grain-filling stage, the rice had high BCF values (> 1) for Cd and Zn. The target hazard quotient (THQ) of ingestion peaked for Cd and reached its minimum level for Zn in not only in adults but also in children. The THQ was ranked as Cd > Cu > Pb > Cr > Zn for both adults and children. The hazard index values for adults and children for the five heavy metals were 1.81 × 10-3 and 1.55 × 10-3, respectively, indicating that these metals have little effect on the human body. The lifetime carcinogenic risk values for local adults and children were 4.28 × 10-5 and 5.92 × 10-5, respectively, both of which were within the tolerable to acceptable risk range. In summary, obvious hazards for local adults and children were not observed in this study. Considering the total amount and chemical forms of Cd, it is necessary to notify the appropriate departments about the possible rice contamination caused by Cd in the soil.

Risk assessment of nitrites for the Austrian adult population with probabilistic modelling of the dietary exposure

Nitrites are present in the food chain as naturally occurring species or contaminants. Additionally, sodium and potassium nitrites are authorised food additives. Nitrites exert acute toxicity through methemoglobinemia or cardiovascular effects, chronic toxicity associated with endocrine, reproductive and developmental effects and have been classified as probable gastric carcinogens. Ingestion of food and water are the main sources of human exposure. This study comprises a tiered risk assessment of nitrites for the Austrian adult population, along with the identification of the food categories most contributing to their intake. The dietary exposure, based on Austrian occurrence and consumption data, was modelled with the Monte Carlo simulation method. In an additional scenario, data gaps were addressed with the usage of occurrence data published by the European Food Safety Authority and from the available literature to account for the exposure from all sources. Risk estimates regarding only the exposure to nitrite additives and to contaminated water indicate low level of concern. However, when exposure from all sources is considered, the estimated exposure is elevated and exceeds the Acceptable Daily Intake for high consumers. Mean exposure attributed to the use of nitrites as additives accounts for only a very small proportion of the total intake.

English

The main sources of human exposure to aluminum are found in the extensive presence of the metal in the environment and its growing industrial applications. The present study was carried out to determine the effectiveness of the Thymus vulgaris L. extract in alleviating aluminum chloride (AlCl3) toxicity on biochemical and antioxidant parameters. The experiment’s rats were divided into five groups: a control group; an intoxicated group (300 mg AlCl3/kg bw); and three other groups which were given AlCl3 (300mg/kg/bw) then T. vulgaris. L extract (T.v), Malic Acid (MA) and Vitamin E (Vit E) at a concentration of 150mg/kg/bw. Each group was given its respective dosage, daily for 90 days. The results showed a significant decrease in the body/liver/kidney weights, the plasma total protein (T. Protein) and albumin (Alb) levels (p≤0.05) in the intoxicated rats group. However, a significant increase in the plasma uric acid (Uac), alkaline (AlP) and acid phosphatase (AcP) levels was noted (p≤0.05) in the same group. The amount of aluminum, TBARS and nitrate/nitrite (NO) in the liver and kidney tissues of the rats treated with AlCl3 was also found to have increased (p≤0.05), while the levels of glutathione peroxidase (GSH-Px) and glutathione transferase (GSH-St) have decreased significantly (p≤0.05). These altered parameters were restored in the rats treated with the T. vulgaris L. extract. Therefore, due to these beneficial effects, T. vulgaris L. could potentially be used to antagonize AlCl3 toxicity. Key words: Thymus vulgaris L., aluminum chloride, oxidative stress, malic acid, vitamin E.  

Ochratoxin A in the Portuguese Wine Market, Occurrence and Risk Assessment

ABSTRACTOchratoxin A (OTA) is mainly found in cereals and cereal-based foodstuffs, but also in wine. Being one of the most consumed alcoholic drinks in Portugal and one of the main sources of human exposure to OTA, wine monitoring and exposure studies are essential. The analytical methodology consisted of the direct injection of the filtered samples into the liquid chromatograph, equipped with fluorescent detection (LC-FLD). Linearity was adequate, both in mobile phase and in matrix-matched solutions, with R2 values higher than 0.997. The limits of detection were 0.08 and 0.39 µg/L for white and red wine, respectively and recoveries were above 91.9%. One hundred wine samples acquired on the Portuguese market were investigated. In 5 samples the OTA was detected, with the red wine presenting higher frequency of contamination. Regarding the risk to human health it was observed that the estimated weekly intake (EWI) is considerably lower than the established tolerable weekly intake (TWI).

Estimation of Radon Exhalation Rate, Radium Activity and Uranium Concentration in Biscuit Samples in Iraq

Introduction: Radioisotopes are naturally the main sources of human exposure to external and internal radiation. Biscuit is a type of food that is widely distributed in all markets, especially in the markets of Iraq. Therefore, the current study aimed to measure the radiation level of some nuclei in biscuit samples and determine the radiation risks that may be caused by this snack. Material and Methods: This study aimed to evaluate the concentration of alpha radiation activity in 22 different samples of biscuits collected from the markets in Iraq. The analysis of radium activity and radon exhalation rate was performed by employing alpha-sensitive CR-39 plastic track detectors. Results: The effective radium values ranged within 23.312-200.44 Bq/kg with a mean value of 58.927 Bq/kg. Radon emission values for the mass unit was within the range of 0.172-1.515 𝐵𝑞/kg.h, with a mean of 0.445 Bq /kg.h, while radon emission values for the surface unit were 3.988-34.3 𝐵𝑞 /𝑚2.h, with a mean of 10.081 Bq /m2.h. The uranium concentrations found in these samples were within the range of 0.02-0.172 ppm with a mean value of 0.05 ppm. Moreover, there was a direct relationship between radium activity and radon exhalation rate. Additionally, the findings showed that uranium correlated positively with radium activity. Conclusion: The results of the present study were within internationally permissible limits. Therefore there is no risk of consumption of biscuits on human health. However, we must use modern techniques and techniques to reduce radiation risk.