Assessment of ecotoxicological effects of Fojo coal mine waste elutriate in aquatic species (Douro Coalfield, North Portugal).

Introduction: The exploitation of anthracite A in the Pejão mining complex (Douro Coalfield, North Portugal) resulted in the formation of several coal waste piles without proper environmental control. In 2017, a new pedological zonation emerged in the Fojo area, after the ignition and self-burning of some of the coal waste piles, namely: unburned coal waste (UW); burned coal waste, and a cover layer (BW and CL, respectively); uphill soil (US); mixed burned coal waste (MBW); downhill soil (DS). This study aimed to evaluate the toxic effects of 25 soil elutriates from different pedological materials. Methods: Allivibrio fischeri bioluminescence inhibition assay, Lemna minor growth inhibition assay, and Daphnia magna acute assay were used to assess the toxicity effects. Additionally, total chlorophyll and malondialdehyde (MDA) content and catalase (CAT) activity were also evaluated in L. minor. Results and Discussion: The results obtained from each endpoint demonstrated the extremely heterogeneous nature of soil properties, and the species showed different sensibilities to soil elutriates, however, in general, the species showed the same sensitivity trend (A. fischeri > L. minor > D. magna). The potentially toxic elements (PTE) present in the soil elutriates (e.g., Al, Pb, Cd, Ni, Zn) affected significantly the species understudy. All elutriates revealed toxicity for A. fischeri, while US1 and UW5 were the most toxic for L. minor (growth inhibition and significant alterations in CAT activity) and D. magna (100% mortality). This study highlights the importance of studying soil aqueous phase toxicity since the mobilization and percolation of bioavailable PTE can cause environmental impacts on aquatic ecosystems and biota.

Phytotoxicity of coal waste elutriates (Douro Coalfield, North Portugal) in Lactuca sativa.

One of the most important mining areas in the Douro Carboniferous Basin is the Pejão Coalfield. In the summer of 2017, a wildfire promoted the ignition and self-burning some of the coal waste piles in the area and caused important environmental changes, promoting a new heterogenic pedological zonation. This study aims to assess the ecotoxicological effects of 25 soil elutriates from these different soil types in seed germination and individual (emergence, growth, and morphologic alterations) and subindividual parameters in Lactuca sativa. The different evaluated endpoints were differently affected regarding the soil elutriate revealing the high heterogeneity of soil characteristics. The presence of different potentially toxic elements (e.g., Cd, Cr, Pb, Zn) in soil elutriates, even in low concentrations, caused effects on L. sativa development. Unburned coal wastes and downhill soil elutriates were able to inhibit the germination of L. sativa and affect them individually and sub-individually (decrease in size, biomass, and presence of morphological alterations). Additionally, it was observed that all soil elutriates induce a decrease in root size. The results highlight the importance of using elutriate samples in phytotoxicity studies of coal mining waste, since the tailings lixiviate may reduce plant establishment and growth, affecting the terrestrial ecosystems. The integrated use of seed germination assays with the analysis of morphological and biochemical alterations in plants proved to be sensitive parameters to evaluate the phytotoxicity of coal mining wastes.

From data to insight: Exploring contaminants in different food groups with literature mining and machine learning techniques.

Food remains a major source of human exposure to chemical contaminants that are unintentionally present in commodities globally, despite strict regulation. Scientific literature is a valuable source of quantification data on those contaminants in various foods, but manually summarizing the information is not practicable. In this review, literature mining and machine learning techniques were applied in 72 foods to obtain relevant information on 96 contaminants, including heavy metals, polychlorinated biphenyls, dioxins, furans, polycyclic aromatic hydrocarbons (PAHs), pesticides, mycotoxins, and heterocyclic aromatic amines (HAAs). The 11,723 data points collected from 254 papers from the last two decades were then used to identify the patterns of contaminants distribution. Considering contaminant categories, metals were the most studied globally, followed by PAHs, mycotoxins, pesticides, and HAAs. As for geographical region, the distribution was uneven, with Europe and Asia having the highest number of studies, followed by North and South America, Africa and Oceania. Regarding food groups, all contained metals, while PAHs were found in seven out of 12 groups. Mycotoxins were found in six groups, and pesticides in almost all except meat, eggs, and vegetable oils. HAAs appeared in only three food groups, with fish and seafood reporting the highest levels. The median concentrations of contaminants varied across food groups, with citrinin having the highest median value. The information gathered is highly relevant to explore, establish connections, and identify patterns between diverse datasets, aiming at a comprehensive view of food contamination.

Occurrence of polycyclic aromatic hydrocarbons, microplastics and biofilms in Alqueva surface water at touristic spots.

Freshwater pollution is a huge concern. A study aiming to evaluate physico-chemical characteristics, microbiota, occurrence of two groups of persistent environmental pollutants with similar chemical properties (polycyclic aromatic hydrocarbons- PAHs and microplastics - MPs) in Alqueva's surface water was performed during 2021. Water samples were collected at three spots related to touristic activities (two beaches and one marina) during the Winter, Spring, Summer and Autumn seasons. In addition, the presence of biofilms on plastic and natural materials (stone, wood/ vegetal materials) were assessed and compared. Water quality based on physicochemical parameters was acceptable with a low eutrophication level. PAHs concentration levels were lower than the standard limits established for surface waters by international organizations. However, carcinogenic compounds were detected in two sampling locations, which can pose a problem for aquatic ecosystems. PAHs profiles showed significant differences when comparing the dry seasons with the rainy seasons, with a higher number of different compounds detected in Spring. Low molecular weigh compounds, usually associated with the atmospheric deposition and petroleum contamination, were more prevalent. MPs were detected in all samples except one during the Winter season. The polymers detected were poly(methyl-2-methylpropenoate), polystyrene, polyethylene terephthalate, polyamide, polypropylene, styrene butadiene, polyvinyl chloride and low /high density polyethylene with the last being the most frequent. Biofilms were more often detected on plastics than on natural materials. In addition, biofilms detected on plastics were more complex with higher microbial diversity (e.g., bacteria, fungi/yeast and phytoplancton organisms) and richer in extrapolymeric material. Based on morphological analysis a good agreement between microbiota and microorganism present in the biofilms was found. Among microbiota were identified microorganisms previously linked to plastic and PAHs detoxification suggesting the need for further studies to evaluate the viability of using biofilms as part of a green bioremediation strategy to mitigate water pollution.

Wildfires effects on organic matter of soils from Caramulo Mountain (Portugal): environmental implications.

The investigation about wildfires has demonstrated that research should include studies on the overall assessment of the processes, thus promoting the public awareness about impacts. The aim of this study is to assess the changes on the carbon content of soils affected by wildfires in Caramulo Mountain (Portugal) to therefore identify the environmental impacts arisen from those changes. Soils from different parent rocks, affected and non-affected by wildfires, were collected. Petrographic and geochemical methods were used to identify changes caused by the wildfires in the organic fraction of soils. The results demonstrate that changes in soils composition after wildfires include the production of charcoal and pyrogenic polycyclic aromatic hydrocarbons (PAH). The incorporation of charcoal from biomass burning in soils overtime and the production of pyrolytic PAH are of environmental concern since these compounds are known to be harmful to the environment and ecosystems and are human carcinogens. The concentration of BkF-benzo[k]fluoranthene, known as probable human carcinogen, exceeds the reference values for contaminated soils. Once in soils these compounds can be removed by percolation affecting waters and, consequently, biodiversity and human health.

Acute and chronic toxicity assessment of haloacetic acids using Daphnia magna.

Haloacetic acids (HAAs) are undesirable disinfection by-products (DBPs), released into aquatic ecosystems from various anthropogenic and natural sources. The aim of this study was to examine the ecological risk of exposure to three HAAs commonly detected in water, such as monobromoacetic acid (MBA), monochloroacetic acid (MCA), and trichloroacetic acid (TCA), in in vivo acute and chronic toxicity tests using Daphnia magna as a model. Acute tests showed that MBA was the most toxic of these compounds followed by MCA and TCA as evidenced by immobilization. Aquatic organisms in natural conditions might be exposed simultaneously to numerous compounds; thus, binary mixtures of selected HAAs and a ternary mixture of these were tested. Concentration addition (CA) and independent action (IA) models were used for a predictive assessment of mixture toxicity. Data demonstrated that CA appeared to be the most reliable indicator for HAAs binary and ternary mixtures suggestive of an additive behavior. Median effective concentration (EC50) values from the mixed exposure tests were significantly lower than results obtained from single tests for all three HAAs where an increase of toxicity greater than 50%. Multigenerational chronic tests were also performed exposing daphnids to the ternary mixture of HAAs. A markedly decreased sexual maturity and number of offspring and broods per daphnid especially in the second generation were noted.

Application of a fast and cost-effective in situ derivatization method prior to gas chromatography with mass spectrometry to monitor endocrine disruptors in water matrices.

This work deals with the optimization of a rapid, cost-effective, and eco-friendly gas chromatography with mass spectrometry method for the simultaneous determination of four endocrine disruptor compounds in water matrices: estrone, 17ß-estradiol, 17α-ethinylestradiol, and bisphenol A, that are currently considered to be of main concern in the field of water policy and that could became candidates for future regulations. The method involves simultaneous derivatization and extraction of compounds by dispersive liquid-liquid microextraction followed by gas chromatography with mass spectrometry analysis. Derivatization and extraction parameters were optimized with the aid of experimental design approach. An excellent linear response was achieved for all analytes (r(2) ≥ 0.999). Limits of detection and quantification are 0.003-0.005 and 0.0094-0.0164 µg/L, respectively. Intraday precision ranged between 1.1 and 12.6%, whereas interday precision ranged between 0.5 and 14.7%. For accuracy, bias values varied between -15.0 and 13.7%. Recoveries at three concentration levels ranged from 86.4 to 118.2%. The proposed method can be applied to the routine analysis of groundwater, river, sea, tap, and mineral water samples with excellent sensitivity, precision, and accuracy.

Odorant binding proteins: a biotechnological tool for odour control.

The application of an odorant binding protein for odour control and fragrance delayed release from a textile surface was first explored in this work. Pig OBP-1 gene was cloned and expressed in Escherichia coli, and the purified protein was biochemically characterized. The IC50 values (concentrations of competitor that caused a decay of fluorescence to half-maximal intensity) were determined for four distinct fragrances, namely, citronellol, benzyl benzoate, citronellyl valerate and ethyl valerate. The results showed a strong binding of citronellyl valerate, citronellol and benzyl benzoate to the recombinant protein, while ethyl valerate displayed weaker binding. Cationized cotton substrates were coated with porcine odorant binding protein and tested for their capacity to retain citronellol and to mask the smell of cigarette smoke. The immobilized protein delayed the release of citronellol when compared to the untreated cotton. According to a blind evaluation of 30 assessors, the smell of cigarette smoke, trapped onto the fabrics' surface, was successfully attenuated by porcine odorant binding protein (more than 60 % identified the weakest smell intensity after protein exposure compared to ß-cyclodextrin-treated and untreated cotton fabrics). This work demonstrated that porcine odorant binding protein can be an efficient solution to prevent and/or remove unpleasant odours trapped on the large surface of textiles. Its intrinsic properties make odorant binding proteins excellent candidates for controlled release systems which constitute a new application for this class of proteins.

Bisphenol A migration from plastic materials: direct insight of ecotoxicity in Daphnia magna.

Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) whose migration from food packaging is recognized worldwide. However, the real overall food contamination and related consequences are yet largely unknown. Among humans, children's exposure to BPA has been emphasized because of the immaturity of their biological systems. The main aim of this study was to assess the reproductive impact of BPA leached from commercially available plastic containers used or related to child nutrition, performing ecotoxicological tests using the biomonitoring species Daphnia magna. Acute and chronic tests, as well as single and multigenerational tests were done. Migration of BPA from several baby bottles and other plastic containers evaluated by GC-MS indicated that a broader range of foodstuff may be contaminated when packed in plastics. Ecotoxicological test results performed using defined concentrations of BPA were in agreement with literature, although a precocious maturity of daphnids was detected at 3.0 mg/L. Curiously, an increased reproductive output (neonates per female) was observed when daphnids were bred in the polycarbonate (PC) containers (145.1 ± 4.3 % to 264.7 ± 3.8 %), both in single as in multigenerational tests, in comparison with the negative control group (100.3 ± 1.6 %). A strong correlated dose-dependent ecotoxicological effect was observed, providing evidence that BPA leached from plastic food packaging materials act as functional estrogen in vivo at very low concentrations. In contrast, neonate production by daphnids cultured in polypropylene and non-PC bottles was slightly but not significantly enhanced (92.5 ± 2.0 % to 118.8 ± 1.8 %). Multigenerational tests also revealed magnification of the adverse effects, not only on fecundity but also on mortality, which represents a worrying trend for organisms that are chronically exposed to xenoestrogens for many generations. Two plausible explanations for the observed results could be given: a non-monotonic dose-response relationship or a mixture toxicity effect.

Occurrence of bisphenol A, estrone, 17ß-estradiol and 17α-ethinylestradiol in Portuguese rivers.

This study focused on the occurrence of several EDCs including bisphenol A, estrone (E1), the 17ß-estradiol (E2) and 17α-ethinylestradiol (EE2) in fourteen rivers of Portugal. Samples analysis revealed a widespread contamination of BPA especially in Ave, Cávado, Douro, Ferro, Sousa and Vizela Rivers. Achieving 98.4 ng/L for the highest concentration. The estrogens achieved above the method quantification limit (MQL) were E1 in Águeda River and E2 in Ave, Lima and Tâmega Rivers. The maximum concentration detected for E1 was 26.9 ng/L. EE2 was detected only below MQL.

Monitoring pesticide residues in greenhouse tomato by combining acetonitrile-based extraction with dispersive liquid-liquid microextraction followed by gas-chromatography-mass spectrometry.

A multiclass and multiresidue method for pesticide analysis in tomato was validated. Extraction and pre-concentration of the pesticide residues from acetonitrile extracts was performed by using dispersive liquid-liquid microextraction (DLLME) technique, followed by gas chromatography-mass detection. DLLME was performed using carbon tetrachloride as extractive solvent and acetonitrile extract as dispersive solvent, in order to increase enrichment factor of the extraction procedure. Validation parameters indicated the suitability of the method for routine analyses of thirty pesticides in a large number of samples. In general, pesticide recoveries ranged between 70% and 110% and repeatability ranged between 1% and 20%. The proposed method was applied to the monitoring of pesticides in tomatoes grown during winter in greenhouses. Among the compounds considered in this work, cyprodinil was found in tomato at concentrations of 0.33mg/kg, other pesticides like azoxystrobin, fenhexanid, tolyfluanid, λ-cyhalothrin and trifloxystrobin were also detected, but, not quantified.

Impact of intensive horticulture practices on groundwater content of nitrates, sodium, potassium, and pesticides.

A monitoring program of nitrate, nitrite, potassium, sodium, and pesticides was carried out in water samples from an intensive horticulture area in a vulnerable zone from north of Portugal. Eight collecting points were selected and water-analyzed in five sampling campaigns, during 1 year. Chemometric techniques, such as cluster analysis, principal component analysis (PCA), and discriminant analysis, were used in order to understand the impact of intensive horticulture practices on dug and drilled wells groundwater and to study variations in the hydrochemistry of groundwater. PCA performed on pesticide data matrix yielded seven significant PCs explaining 77.67% of the data variance. Although PCA rendered considerable data reduction, it could not clearly group and distinguish the sample types. However, a visible differentiation between the water samples was obtained. Cluster and discriminant analysis grouped the eight collecting points into three clusters of similar characteristics pertaining to water contamination, indicating that it is necessary to improve the use of water, fertilizers, and pesticides. Inorganic fertilizers such as potassium nitrate were suspected to be the most important factors for nitrate contamination since highly significant Pearson correlation (r = 0.691, P < 0.01) was obtained between groundwater nitrate and potassium contents. Water from dug wells is especially prone to contamination from the grower and their closer neighbor's practices. Water from drilled wells is also contaminated from distant practices.

Optimization of conditions for anthocyanin hydrolysis from red wine using response surface methodology (RSM).

Optimization of conditions for anthocyanin hydrolysis from red wine was investigated using response surface methodology. The aglycon forms of the anthocyanins were quantified by high-performance liquid chromatography with diode array detection. The combined effects of three independent variables, HCl amount, heating temperature, and hydrolysis time, were studied using a 2(3) full-factorial central composite design. Anthocyanin hydrolysis yield depended mainly on the heating temperature and time of hydrolysis. HCl amount was the factor that least influenced the hydrolysis of anthocyanins. From experimental results, the maximum yield of anthocyanidins was reached with 9.8 mL of HCl (32% v/v), a heating temperature of 166.2 °C, and a hydrolysis time of 46.6 min. Five anthocyanidins, namely, delphinidin, cyanidin, petunidin, peonidin, and malvidin, were quantified in red wine. The reliability of the method was confirmed by recovery experiments, performed under optimal conditions. Recoveries indicated that anthocyanidins resisted the hydrolysis conditions.

Salmonella: the forgotten pathogen: health hazards of compliance with European bathing water legislation.

The increasing demands on recreational waters have made microbial contamination a matter of public and scientific concern. This study aimed to search for Salmonella spp. in waters classified according EU Directive 2006/7/EC, in order to assess associations between its prevalence and the concentration of the non-pathogenic new faecal indicators: Escherichia coli and intestinal enterococci. Although a statistically significant association was observed Salmonella was detected on beaches classified as "Good" (9.3%) and "Excellent" (14.4%) which compromises the idea that faecal indicators can be predictors of pathogens. Attending the high prevalence of Salmonella found (23.1%) it seemed important to improve the efficiency of the conventional analytical method (ISO 6340:1995), comparing its draft with SML-VIDAS Salmonella and two new chromogenic media: AES Salmonella Agar Plate (ASAP) and Simple Method Salmonella (SMS). ASAP showed the higher efficiency and can be recommended for a faster detection and presumptive identification of salmonellae in bathing waters.

Bathing waters: new directive, new standards, new quality approach.

Bathing water quality is an important public health issue, mainly because of fecal contamination. In 2006, the European Commission (EC) adopted a new directive with respect to recreational bathing waters that calls for stricter standards and reduces the number of laboratory tests done in routine beach monitoring from nineteen to two bacterial indicators, namely, Escherichia coli and intestinal enterococci, replacing policies of the EC Bathing Water Directive that have existed since 1976. Our practice in Portugal is in line with this international development, and this study demonstrates the equivalency of the new bacteriological parameters with the old. The water quality of 25 coastal beaches was surveyed using both new and old microbiological indicators of fecal contamination. Statistical analysis demonstrated equivalency of the results obtained for fecal coliforms with Escherichia coli and for fecal streptococci with intestinal enterococci.