Heavy metals and potential health risk assessment of Lactuca sativa and Daucus carrota from soil treated with organic manures and chemical fertilizer.

The large-scale production of food crops with heavy application of chemical fertilizers in the effort to meet the astronomical increase in food demands may be counterproductive to the goal of food security. This study investigated the effect of different soil treatments on the levels of heavy metals (Cr, Cu, Fe, Ni, Pb, and Zn) in two types of vegetables Lactuca sativa (lettuce) and Daucus carrota (carrot). The potential carcinogenic and non-carcinogenic health risks from their consumption were also evaluated. Planting experiment was set up in a randomized block design, with different soil treatments of soil + cow dung (CD), soil + sewage sludge (SS), soil + chemical fertilizer (nitrogen-phosphorus-potassium (NPK)), and untreated soil (UNTRD). The vegetables were harvested at maturity, washed with distilled water, and subjected to an acid digestion process before the levels of heavy metals were measured by inductively coupled plasma spectrometry (ICP-MS). The mean concentrations of the metals in the vegetables across all treatments were below the maximum permissible limits. The pattern of heavy metal accumulation by the vegetables suggested that the lettuce from SS treatment accumulated higher concentrations of heavy metals like Cr (0.20 mg/kg), Cu (3.91 mg/kg), Ni (0.33 mg/kg), and Zn (20.44 mg/kg) than carrot, with highest concentrations of Fe (90.89 mg/kg) and Pb (0.16 mg/kg) recorded in lettuce from NPK treatment. The bioaccumulation factor (BAF) showed that lettuce, a leafy vegetable, has bioaccumulated more heavy metals than carrot, a root vegetable. The BAF was generally below the threshold value of 1 in both vegetables, except in lettuce from NPK and CD treatments and carrot from NPK treatments, with BAF values of 1.6, 1.69, and 1.39, respectively. The cancer risk assessment factors were well below the unacceptable maximum range of 10-4 suggesting that consuming these vegetables might not expose an individual to potential risk of cancer development. The hazard quotient estimations were below the threshold values of 1 for all heavy metals; however, the hazard index (HI) values of 1.27 and 1.58 for lettuce from NPK and SS treatments indicate a potential non-carcinogenic health risk to consumers from intake of all the heavy metals.

Risk assessment for uptake and accumulation of pharmaceuticals by baby leaf lettuce irrigated with reclaimed water under commercial agricultural activities.

The use of reclaimed water to irrigate agricultural crops has increased in recent years as a consequence of water shortage constituting a potential risk for human health. The main objective of this study was to evaluate the impact on the soil-plant system and determining the accumulation of carbamazepine (CBZ), diclofenac (DCF), ketoprofen (KTP) and naproxen (NPX) in the edible part of lettuce under commonly used agricultural practices in commercial production. For this purpose, red oak baby lettuce (Lactuca sativa L.) was irrigated with reclaimed water fortified with different concentrations of pharmaceuticals. The study was carried out in two different scenarios: soil and tray. The tray experiments were conducted with substrate and took place at three different seasons of the year. Lettuce tissue sampled from these experiments were analysed 3 times during the lettuce growing cycle (first, second and third harvest). The practices of first harvest regrowth were also evaluated. For all experiments, CBZ showed the highest accumulation in lettuce leaves of the pharmaceuticals tested, showing a correlation between irrigation exposure time and pharmaceutical uptake. Unexpectedly, DCF was the compound with the highest uptake levels after regrowth practices. Results suggested that pharmaceuticals uptake could be directly associated with the irrigation method and possible accumulation in soil and substrates, while concentration of pharmaceuticals in substrates were 10 times higher. Based on the concentration values detected in lettuce leaves, the risk assessment suggests that no compounds imply any risk to human health, except CBZ for those on vegetarian diets in the tray scenario. Although commercial agricultural practices are usually not considered with regards to risk reduction, in this experiment we demonstrated that climatic conditions are a key factor in pharmaceuticals uptake and different agricultural practices (soil cropping and drip irrigation) can limit the presence of pharmaceutical compounds in crops.

Assessment of Foliar Uptake and Accumulation of Airborne Polyaromatic Hydrocarbons Under Laboratory Conditions.

Urban horticulture and community gardening have become more and more popular in the past years, however, the risk of bioaccumulation of atmospheric polyaromatic hydrocarbons (PAHs) in vegetables grown in polluted areas cannot be neglected. In our study, the No. 227 OECD GUIDELINE FOR THE TESTING OF CHEMICALS: Terrestrial Plant Test: Vegetative Vigour Test was followed to assess foliar uptake of PAHs from aqueous extract of an urban aerosol. Using lettuce (Lactuca sativa) as a test organism, significant accumulation was experienced. The highest bioconcentration factors (BCFs) were experienced for naphthalene and for anthracene, pyrene and fluoranthene showed the lowest bioaccumulation potential. BCF of each PAH showed strong correlation with molecular weight. The standard protocol defined by the Guideline made it possible to assess bioaccumulation pattern under controlled laboratory conditions.

Pesticide Residues and Health Risk Assessment in Tomatoes and Lettuces from Farms of Metropolitan Region Chile.

Over the last years, the detection of pesticide residues in the official food surveillance programs of Chile has been increased, mainly in fresh vegetables such as tomatoes and lettuces. The Metropolitana Region of Chile presents the highest detections in the country. The lack of evaluations of toxicological risks in human health have increased uncertainty of the potential effects of pesticides exposures in the Chilean population. This research aims to determinate health risks assessment of pesticide residues associated to tomatoes and lettuces produced in Metropolitana Region. The findings of this study reveal that tomatoes and lettuces cultivated in the MR show more than 50% of samples with one or multiple pesticides residues. From the total samples, 16% were over the Chilean Maximum Residue Levels (MRLs). The main pesticides detected in tomatoes and lettuces were methamidophos, methomyl, difenoconazole, cyprodinil and boscalid. The results obtained using the official data of the Ministry of Health of Chile (MINSAL) compared to the World Health Organization (WHO), describe relevant risks through the Estimated Daily Intakes (EDI), Hazard Quotients (HQ) and Hazard Index (HI) for the Chilean population due to high concentrations of methamidophos, methomyl and cyprodinil. More restrictions for the use of methamidophos, methomyl, difenoconazole, cyprodinil and boscalid and effective control programs should be implemented in order to mitigate the impacts on the Chilean population.

Dynamics and dietary risk assessment of thiamethoxam in wheat, lettuce and tomato using field experiments and computational simulation.

Thiamethoxam is a widely used pesticide applied to different field crops. To inform risk assessment for this pesticide across relevant crops, we usually rely on field trials, which require time, costs and energy. For providing reliable data across crops and reduce experimental efforts, field trials should be complemented with dynamic modelling. In the present work, we hence focused on combining field trials with dynamic modelling to simulate mass evolutions of the pesticide-plant-system for thiamethoxam applied to wheat, lettuce and tomato as three major food crops. Field trials were conducted with QuEChERS (quick, easy, cheap, effective, rugged and safe) liquid chromatography-mass spectrometry, which gave consistent maximum residue concentrations for thiamethoxam in wheat, lettuce and tomato. We used these residues to evaluate the related dietary risk of humans consuming these food crops. Our results indicated that thiamethoxam did not provide any unacceptable dietary risk for humans across these three food crops, which is in line with findings from previous studies. Results for the studied crops could be extrapolated to other crops and with that, our study constitutes a cost- and time-efficient way of providing reliable input for risk assessment of pesticides across crops, which is relevant for both practitioners and regulators.

Bioavailability Assessment of Copper, Iron, Manganese, Molybdenum, Selenium, and Zinc from Selenium-Enriched Lettuce.

Cu, Fe, Mn, Mo, Selenium (Se), and Zn bioavailability from selenate- and selenite-enriched lettuce plants was studied by in vitro gastrointestinal digestion followed by an assay with Caco-2 cells. The plants were cultivated in the absence and presence of two concentrations (25 and 40 µmol/L of Se). After 28 days of cultivation, the plants were harvested, dried, and evaluated regarding the total concentration, bioaccessibility, and bioavailability of the analytes. The results showed that biofortification with selenate leads to higher Se absorption by the plant than biofortification with selenite. For the other nutrients, Mo showed high accumulation in the plants of selenate assays, and the presence of any Se species led to a reduction of the plant uptake of Cu and Fe. The accumulation of Zn and Mn was not strongly influenced by the presence of any Se species. The bioaccessibility values were approximately 71%, 10%, 52%, 84%, 71%, and 86% for Cu, Fe, Mn, Mo, Se, and Zn, respectively, and the contribution of the biofortified lettuce to the ingestion of these minerals is very small (except for Se and Mo). Due to the low concentrations of elements from digested plants, it was not possible to estimate the bioavailability for some elements, and for Mo and Zn, the values are below 6.9% and 3.4% of the total concentration, respectively. For Se, the bioavailability was greater for selenite-enriched than selenate-enriched plants (22% and 6.0%, respectively), because selenite is biotransformed by the plant to organic forms that are better assimilated by the cells.

Assessment of microcystin contamination of Amaranthus hybridus, Brassica oleracea, and Lactuca sativa sold in markets: a case study of Zaria, Nigeria.

Microcystins (MCs) are toxic secondary metabolites produced by several cyanobacteria genera that have been implicated in human cancer cases and deaths. Human exposure routes include direct contact with contaminated water and the consumption of contaminated food. The present study investigated the presence of MCs in three commonly consumed vegetables at the point of sale in market places as a means of assessing the direct human health risk of buying vegetables. Overall, 53% of the vegetables obtained from different markets had levels of MCs that were higher than 1.00 µg/g. Amaranthus hybridus L. (smooth amaranth) had the highest MC concentration (4.79 µg/g) in samples obtained from Sabon Gari Market, while Lactuca sativa L. (garden lettuce) had the lowest concentration (0.17 µg/g) in samples obtained from Dan-Magaji Market. The highest total daily intake (TDI) of MCs by an adult weighing 60 kg was 3.19 µg/kg for A. hybridus, 1.41 µg/kg for Brassica oleracea L. (cabbage), and 2.94 µg/kg for L. sativa. The highest TDI of MCs for a child weighing 25 kg was highest in A. hybridus (1.91 µg/kg), followed by L. sativa (1.77 µg/kg). These results revealed that the consumption of vegetables sold in markets in Zaria, Nigeria, during the dry season represents a major exposure route to MCs. There is, therefore, an urgent need to develop policies and monitoring strategies to tackle this problem in developing countries.

Assessment of concentration of polycyclic aromatic hydrocarbons (PAHs) in vegetables from farms in Accra, Ghana.

Ingestion of leafy vegetables is an important dietary component of most Africans due to its health benefits. High levels of polycyclic aromatic hydrocarbons (PAHs) in the leafy vegetables may pose a significant health hazard to the consumers. Rose/Hibiscus, Chinese cabbage, lettuce, and garden egg leaves from farms along the Nima Creek, Accra, were selected. At each sampling site, the vegetable was uprooted and cut into leaves, stem, and root and analyzed differently. The GC-MS method was employed in the identification and quantification of 16 PAHs in the samples. The analysis was done at CSIR - Water Research Institute Organic Laboratory. The results obtained show concentrations of acenapththylene, acenapthene, benzo[a]anthracene, benzo[b]fluoranthene, and benzo[a]pyrene (except chrysene and pyrene which were found in garden egg leaves and Chinese cabbage respectively), while naphthalene was detected in all the vegetables. The mean concentration of phenanthrene in leaves, stem, and roots of Chinese cabbage vegetable varies according to the following order: roots (0.744 ± 0.16 µg/kg) ≥ leaves (0.598 ± 1.21 µg/kg) ≥ stem (0.327 ± 1.01 µg/kg). From the results of the isomeric ratios, the source of the PAHs in the leafy vegetables are from mixed sources, i.e., either pyrogenic and petrogenic origins. This calls for the formulation of stringent policies on the importation of over-age vehicles into the countries as well as on the indiscriminate burning of materials containing PAHs.

Determination of the Residue Behavior and Risk Assessment of Chlorfluazuron in Chinese Cabbage, Kale, Lettuce and Cauliflower by UPLC-MS/MS.

Chlorfluazuron is used as a highly effective insect growth regulator to control a variety of crop pests. However, residues of this pesticide have been shown to be harmful to human health. To evaluate the residual dissipation pattern and risk for dietary intake of chlorfluazuron in various vegetables, a solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry method was established to analyze chlorfluazuron residues in Chinese cabbage, Chinese kale, Chinese lettuce, and cauliflower. The sample was extracted with acetonitrile and purified using an SPE amino column. The average recovery of the target sample in the analyzed four vegetables was between 75.0% and 104.1%, and the relative standard deviation was between 2.5% and 9.6%. The precision and accuracy of the analysis met the requirements of residue analysis standards. Dissipation kinetic testing of chlorfluazuron in different vegetables showed a half-life of 2.4-12.6 days, with a rapid dissipation rate. The estimated daily intake of the chlorfluazuron was 0.753-1.661 µg/(kg bw·d), and the risk quotient was 0.15-0.35. It showed that chlorfluazuron had a low risk of chronic dietary intake from vegetables in different populations in China. The results of this study has described the degradation rate of chlorfluazuron in four vegetables, evaluated the risk of dietary exposure to Chinese residents. Therefore, it provides supporting data and empirical basis for guiding the reasonable use of chlorfluazuron in vegetable production and in evaluating its dietary intake risk in vegetables.

Remediated marine sediment as growing medium for lettuce production: assessment of agronomic performance and food safety in a pilot experiment.

BACKGROUND: The use of reclaimed dredged sediments as growing media may offer a profitable alternative to their disposal as a waste and at the same time meets the need of peat-substitute substrates in horticulture. When sediments are reused to cultivate food crops, issues related to human health rise due to potential accumulation of contaminants in the product. This pilot study aimed at verifying the suitability of a reclaimed dredged port sediment, used pure or mixed with peat, as a growing medium for lettuce cultivation. RESULTS: The pure sediment caused a reduction in crop yield, probably due to its unsuitable physical properties, whereas the mixture sediment-peat and pure peat resulted in the same yield. Although the sediment contained potentially phytotoxic heavy metals and some organic pollutants, no symptoms of plant toxicity were noted. Besides, no organic contaminants were detected in lettuce heads, and heavy metals amounts were not hazardous for consumers. Conversely, plants grown in the sediment were particularly rich in minerals like Ca, Mg and Fe, and showed higher concentrations of organic acids and antioxidants. CONCLUSION: The use of the sediment as a growing medium for lettuce was shown to be safe for both inorganic and organic contaminants. Nevertheless, considering crop yield results, the mixture of the sediment with other materials is recommended in order to produce a substrate with more suitable physicochemical properties for vegetable cultivation. © 2019 Society of Chemical Industry.

Use of raw and composted poultry litter in lettuce produced under field conditions: microbiological quality and safety assessment.

Lettuce (Lactuca sativa L.) constitutes one the most important vegetable crops worldwide. Poultry litter is being applied as an economically suitable alternative to nitrogen fertilizers in lettuce cultivation. However, little is known about the effects of this practice over this fresh product safety that is usually consumed as a salad. The aim of this work was to determine the microbiological quality and the nitrate content in lettuce produced, under field conditions, using either raw or composted poultry litter, coming from the same original batch. Two experiments were conducted in the experimental field of Facultad de Ciencias Agrarias (UNL, Santa Fe, Argentina) to assess the effects of recently extracted poultry litter that consisted of broiler chicken manure plus rice husk, or composted for 12 mo. The application amounts were: 20 T ha-1 (T1); 40 T ha-1 (T2); and no application of manure (T). Increasing the applied quantities had also increased the health risk associated with lettuce consumption, due to higher nitrate levels and microbial contamination. However, these risks were reduced by composting the material. Even when lettuce contamination with faecal bacteria was mainly due to the use of poultry litter, the number and incidence of pathogens were reduced when properly composted manure was applied instead of raw one. Increasing the dose of poultry litter applied also increases the health risk in lettuce. Though, when the material is properly composted, its fertilizing capacity is maintained, giving proper yields with lower nitrate levels and microbial contamination by enterobacteria.

An efficient one-step scheme for the purification of major xanthophyll carotenoids from lettuce, and assessment of their comparative anticancer potential.

The foremost problem in carotenoid research is the excessive cost and difficulty of maintaining pure carotenoid compounds. This work presents an economical, efficient, and simplified one-step scheme for the purification of four major xanthophyll carotenoids from lettuce by utilizing preparative thin layer chromatography on Hyflo-Super-Cel: MgO (Heavy): calcium sulfate hemihydrate (9:9:2 w/w) based adsorbent. The mobile phase of acetone: hexane (1:1) provided the perfect separation of major xanthophylls, resulting in 95-96% purity after just single-step separation, with no interference from chlorophylls or other minor carotenoids. The identity of carotenoids was confirmed by absorption spectroscopy, chemical tests and APCI+-MS/MS. The proposed scheme can be used to isolate the carotenoids at the analytical and preparative scale. In anticancer studies, among four xanthophylls, 9-Z-neoxanthin was found most potent for reduction of cell viability of cervical (HeLa) and lung cancer (A549) cells, with IC50 values of 3.8 and 7.5 µM, respectively.

Assessment of trace metals in five most-consumed vegetables in the US: Conventional vs. organic.

Metal concentrations (As, Cd, Pb, Cr, Ba, Co, Ni, Cu, and Zn) in conventional and organic produce were assessed, specifically, five most-consumed vegetables from the US including potato, lettuce, tomato, carrot and onion. They were from four representative supermarkets in a college town in Florida. All vegetables contained detectable metals, while As, Cd, Pb, Cr, and Ba are toxic metals, Co, Ni, Cu, and Zn are nutrients for humans. The mean concentrations of As, Cd, Pb, Cr and Ba in five vegetables were 7.86, 9.17, 12.1, 44.8 and 410 µg/kg for organic produce, slightly lower than conventional produce at 7.29, 15.3, 17.9, 46.3 and 423 µg/kg. The mean concentrations of Co, Ni, Cu, and Zn in five vegetables were 3.86, 58.5, 632, and 2528 µg/kg for organic produce, comparable to conventional produce at 5.94, 68.2, 577, and 2354 µg/kg. For toxic metals, the order followed tomato < lettuce < onion < carrot < potato, with root vegetables being the highest. All metals in vegetables were lower than the allowable concentrations by FAO/WHO. Health risks associated with vegetable consumption based on daily intake and non-carcinogenic risk based on hazard quotient were lower than allowable limits. For the five most-consumed vegetables in the US, metal contents in conventional produce were slightly greater than organic produce, especially for Cd and Pb.

Residue analysis and dietary exposure risk assessment of tebufenozide in stem lettuce (Lactuca sativa L. var. angustana Irish).

Tebufenozide, a newly-developed nonsteroidal ecdysone agonist, is in pre-regulation phase (before approval for use) on stem lettuce in China. Aiming at the safe application of tebufenozide, the dissipation and terminal residue trials on stem lettuce were performed under good agricultural practice (GAP). The dissipation trials shown that tebufenozide was rapidly degraded in stem lettuce, with half-lives of 5.0-8.2 days. Pre-regulation dietary exposure risk assessments were evaluated to recommend maximum residue limits (MRLs) based on risk quotients (RQ) method. Relevant toxicological parameters including ADI (acceptable daily intake) and ARfD (acute reference dose) were applied to assess the potential dietary exposure risk. The results indicated the chronic dietary exposure risk probability (RQc) of tebufenozide ranged from 36.4% to 70.0%. The acute dietary exposure risk probability (RQa) of tebufenozide was 2.88%-8.49% in lettuce stems and 14.0%-20.0% in lettuce leaves, respectively. On the basis of supervised field trial data and dietary exposure risk assessment results, the MRLs of tebufenozide were recommended as 3 mg/kg for lettuce stems and 10 mg/kg for lettuce leaves, respectively. The results demonstrated that the dietary exposure risk of tebufenozide used in stem lettuce under GAP was negligible and would not pose unacceptable health risk to Chinese consumers.

Effect of organic agronomic techniques and packaging on the quality of lamb's lettuce.

BACKGROUND: This research focused on the effect of organic production systems on initial quality and postharvest performance of lamb's lettuce leaves stored in air or under modified atmosphere at refrigerated temperature. Different strategies of organic soil fertility management were compared under the same environmental conditions: (i) a simplified organic production system based on organic commercial fertilizers to recover crop uptake (SB); (ii) an organic production system based on organic matter amendment mainly supplied by animal manure (AM); and (iii) an organic production system based on organic matter amendment supplied by green waste compost (AC). Fully developed lamb's lettuce leaves were harvested and then packed into perforated bags (control in AIR) or in modified atmosphere packaging (MAP) and stored at 4 °C. RESULTS: At harvest, the yield of lamb's lettuce in the AM and AC systems was higher than that in SB. Phenol and dehydroascorbic acid accumulation was observed in the system with the lowest initial supply of organic amendment (SB). Regarding the effect of packaging, AIR conditions maintained the initial quality attributes for a longer period than MAP, which developed off-odours above the threshold of acceptability at 11 days, irrespective of the production system used. CONCLUSION: In general, the initial differences among the production systems were minimal during the postharvest storage. As for the tested packaging systems, AIR successfully maintained the initial quality attributes for a longer period than the MAP. © 2018 Society of Chemical Industry.

Occurrence and risk assessment of antibiotics in water and lettuce in Ghana.

Hospital wastewater and effluents from waste stabilization ponds in Kumasi, Ghana, are directly discharged as low quality water into nearby streams which are eventually used to irrigate vegetables. The presence of 12 commonly used antibiotics in Ghana (metronidazole, ciprofloxacin, erythromycin, trimethoprim, ampicillin, cefuroxime, sulfamethoxazole, amoxicillin, tetracycline, oxytetracycline, chlortetracycline and doxycycline) were investigated in water and lettuce samples collected in three different areas in Kumasi, Ghana. The water samples were from hospital wastewater, wastewater stabilization ponds, rivers and irrigation water, while the lettuce samples were from vegetable farms and market vendors. Antibiotics in water samples were extracted using SPE while antibiotics in lettuce samples were extracted using accelerated solvent extraction followed by SPE. All extracted antibiotics samples were analyzed by HPLC-MS/MS. All studied compounds were detected in concentrations significantly higher (p=0.01) in hospital wastewater than in the other water sources. The highest concentration found in the present study was 15µg/L for ciprofloxacin in hospital wastewater. Irrigation water samples analyzed had concentrations of antibiotics up to 0.2µg/L. Wastewater stabilization ponds are low technology but effective means of removing antibiotics with removal efficiency up to 95% recorded in this study. However, some chemicals are still found in levels indicating medium to high risk of antibiotics resistance development in the environment. The total concentrations of antibiotics detected in edible lettuce tissues from vegetable farms and vegetable sellers at the markets were in the range of 12.0-104 and 11.0-41.4ng/kg (fresh weight) respectively. The antibiotics found with high concentrations in all the samples were sulfamethoxazole, erythromycin, ciprofloxacin, cefuroxime and trimethoprim. Furthermore, our study confirms the presence of seven antibiotics in lettuce from irrigation farms and markets, suggesting an indirect exposure of humans to antibiotics through vegetable consumption and drinking water in Ghana. However, estimated daily intake for a standard 60kg woman was 0.3ng/day, indicating low risk for human health.

[Socioeconomic status, eating patterns, and heavy metals exposure in women of childbearing age in Cali, Colombia].

INTRODUCTION: Global increase in food and water pollution is associated with health risk, which depends on the concentration, the dose, and the exposure time. This has raised concerns about the possible long-term effects of chronic exposure to low concentrations of heavy metals, such as lead, cadmium and mercury. OBJECTIVE: To explore the relationship among socioeconomic status, eating patterns, and exposure to heavy metals among a population of women in Cali, Colombia. MATERIALS AND METHODS: A total of 233 non-pregnant women of childbearing age living in the Aguablanca district of Cali, Colombia, were enrolled in the study. We gathered sociodemographic data, as well as information on housing conditions, exposure to heavy metals, frequency of food intake, and anthropometric measurements. Samples of lettuce, cabbage and fish (tilapia and butterfish) were collected to determine lead, cadmium, and mercury concentrations. Descriptive and multiple correspondence analyses were performed to establish eating patterns. RESULTS: Fish was served in each of the three main meals of the day, with a bigger serving at lunch time. Cadmium was found in three samples of butterfish at levels below the acceptable. Of those who ate fish more than once a week, 11.1% bought the product at a cadmium-positive store. The multiple correspondence analysis showed a positive relationship between being black and consuming butterfish and tilapia more than once per week. CONCLUSIONS: The findings showed that the studied population had access to heavy metal-contaminated food, which combined with the women's cultural eating patterns, socioeconomic status, and metabolic characteristics led to a greater vulnerability to the effects of heavy metals exposure.

Potential human health risk assessment of cylindrospermopsin accumulation and depuration in lettuce and arugula.

The cyanobacterial toxin cylindrospermopsin (CYN) has become a globally important secondary metabolite due to the negative effect it has on human and animal health. As a means of evaluating the risk of human exposure to CYN, the bioaccumulation and depuration of the toxin in lettuce (Lactuca sativa L.) and arugula (Eruca sativa Mill.) were investigated, after irrigation with contaminated water. The vegetables were irrigated for 7days with CYN (3, 5 and 10µg/L) contaminated water (bioaccumulation phase), and subsequently, irrigated for 7days with uncontaminated distilled water (depuration phase). In general, the bioaccumulation of CYN in both vegetables decreased with increasing exposure concentration. Bioconcentration factor (BCF) of CYN increased with the progression of the experiment at 3.0µg/L CYN, while the reverse occurred at 5 and 10µg/L CYN. In arugula, BCF increased at all CYN exposure concentrations throughout the study. The depuration of CYN decreased with increasing exposure concentration but was highest in the plants of both species with the highest bioaccumulation of CYN. Specifically, in plants previously irrigated with water contaminated with 3, 5 and 10µg/L CYN, the depuration of the toxin was 60.68, 27.67 and 18.52% for lettuce, and 47, 46.21 and 27.67% for arugula, respectively. Human health risks assessment revealed that the consumption of approximately 10 to 40g of vegetables per meal will expose children and adults to 1.00-6.00ng CYN/kg body mass for lettuce and 2.22-7.70ng CYN/kg body mass for arugula. The irrigation of lettuce and arugula with contaminated water containing low CYN concentrations constitutes a potential human exposure route.

Condición socioeconómica, patrones de alimentación y exposición a metales pesados en mujeres en edad fértil de Cali, Colombia / Socioeconomic status, eating patterns, and heavy metals exposure in women of childbearing age in Cali, Colombia

Resumen Introducción. La contaminación del agua y de los alimentos constituye un riesgo creciente para la salud a nivel mundial. Dicho riesgo varía según las concentraciones y las dosis de los contaminantes y el tiempo de exposición, especialmente por los posibles efectos a largo plazo debidos a la exposición crónica a bajas concentraciones de metales pesados como el plomo, el cadmio y el mercurio. Objetivo. Explorar la relación entre la condición socioeconómica, los patrones de alimentación y la exposición a metales pesados en una población de mujeres de Cali. Materiales y métodos. Participaron 233 mujeres en edad fértil, no embarazadas, residentes en el distrito de Aguablanca, Cali, Colombia. Se recolectó información sociodemográfica, así como sobre las condiciones de la vivienda, la exposición a metales pesados, la frecuencia de consumo de alimentos y las mediciones antropométricas. Para determinar las concentraciones de plomo, cadmio y mercurio, se tomaron muestras de lechuga, repollo y peces (tilapia y 'manteco'). Se hicieron análisis descriptivos y de correspondencias múltiples para establecer los patrones de consumo. Resultados. El pescado se incluía en las tres comidas del día, especialmente en el almuerzo; se encontró cadmio por debajo de los niveles permitidos en tres muestras de 'manteco'. El 11,1 % de quienes consumían pescado una vez o más por semana lo había comprado en un expendio en el cual las muestras fueron positivas para cadmio. Mediante el análisis de correspondencias múltiples, se determinó la presencia de una relación entre el ser de raza negra y el consumo de 'manteco' y tilapia una vez o más por semana. Conclusiones. La población de estudio tuvo acceso a alimentos contaminados con metales pesados. Esto, sumado a las características metabólicas de las mujeres y a sus condiciones socioeconómicas, incrementó su exposición y vulnerabilidad frente a los efectos de la contaminación.

Abstract Introduction: Global increase in food and water pollution is associated with health risk, which depends on the concentration, the dose, and the exposure time. This has raised concerns about the possible long-term effects of chronic exposure to low concentrations of heavy metals, such as lead, cadmium and mercury. Objective: Toexplore the relationship among socioeconomic status, eating patterns, and exposure to heavy metals among a population of women in Cali, Colombia. Materials and methods: A total of 233 non-pregnant women of childbearing age living in the Aguablanca district of Cali, Colombia, were enrolled in the study. We gathered sociodemographic data, as well as information on housing conditions, exposure to heavy metals, frequency of food intake, and anthropometric measurements. Samples of lettuce, cabbage and fish (tilapia and butterfish) were collected to determine lead, cadmium, and mercury concentrations. Descriptive and multiple correspondence analyses were performed to establish eating patterns. Results: Fish was served in each of the three main meals of the day, with a bigger serving at lunch time. Cadmium was found in three samples of butterfish at levels below the acceptable. Of those who ate fish more than once a week, 11.1% bought the product at a cadmium-positive store. The multiple correspondence analysis showed a positive relationship between being black and consuming butterfish and tilapia more than once per week. Conclusions: The findings showed that the studied population had access to heavy metal-contaminated food, which combined with the women's cultural eating patterns, socioeconomic status, and metabolic characteristics led to a greater vulnerability to the effects of heavy metals exposure.

Microcystin-LR bioaccumulation and depuration kinetics in lettuce and arugula: Human health risk assessment.

Microcystin-LR (MC-LR) is one of the most toxic and common microcystins (MCs) variant found in aquatic ecosystems. Little is known about the possibility of recovering microcystins contaminated agricultural crops. The objectives of this study were to determine the bioaccumulation and depuration kinetics of MC-LR in leaf tissues of lettuce and arugula, and estimate the total daily intake (ToDI) of MC-LR via contaminated vegetables by humans. Arugula and lettuce were irrigated with contaminated water having 5 and 10µgL(-1) of MC-LR for 7days (bioaccumulation), and subsequently, with uncontaminated water for 7days (depuration). Quantification of MC-LR was performed by LC-MS/MS. The one-compartment biokinetic model was employed for MC-LR bioaccumulation and depuration data analysis. MC-LR was only accumulated in lettuce. After 7days of irrigation with uncontaminated water, over 25% of accumulated MC-LR was still retained in leaf tissues of plants treated with 10µgL(-1) MC-LR. Total daily toxin intake by adult consumers (60kg-bw) exceeded the 0.04µgMC-LRkg(-1) limit recommended by WHO. Bioaccumulation was found to be linearly proportional to the exposure concentration of the toxin, increasing over time; and estimated to become saturated after 30days of uninterrupted exposure. On the other hand, MC-LR depuration was less efficient at higher exposure concentrations. This is because biokinetic half-life calculations gave 2.9 and 3.7days for 5 and 10µgL(-1) MC-LR treatments, which means 29-37days are required to eliminate the toxin. For the first time, our results demonstrated the possibility of MC-LR decontamination of lettuce plants.