Уточнить поиск
Результаты 1-7 из 7
Uptake and accumulation of four PPCP/EDCs in two leafy vegetables
2013
Dodgen, L.K. | Li, J. | Parker, D. | Gan, J.J.
Many pharmaceutical and personal care products (PPCPs) and endocrine-disrupting chemicals (EDCs) are present in reclaimed water, leading to concerns of human health risks from the consumption of food crops irrigated with reclaimed water. This study evaluated the potential for plant uptake and accumulation of four commonly occurring PPCP/EDCs, i.e., bisphenol A (BPA), diclofenac sodium (DCL), naproxen (NPX), and 4-nonylphenol (NP), by lettuce (Lactuca sativa) and collards (Brassica oleracea) in hydroponic culture, using 14C-labeled compounds. In both plant species, plant accumulation followed the order of BPA > NP > DCL > NPX and accumulation in roots was much greater than in leaves and stems. Concentrations of 14C-PPCP/EDCs in plant tissues ranged from 0.22 ± 0.03 to 927 ± 213 ng/g, but nearly all 14C-residue was non-extractable. PPCP/EDCs, particularly BPA and NP, were also extensively transformed in the nutrient solution. Dietary uptake of these PPCP/EDCs by humans was predicted to be negligible.
Показать больше [+] Меньше [-]Soil contamination by phthalate esters in Chinese intensive vegetable production systems with different modes of use of plastic film
2013
Wang, Jun | Luo, Yongming | Teng, Ying | Ma, Wenting | Christie, Peter | Li, Zhengao
The concentrations of six priority phthalic acid esters (PAEs) in intensively managed suburban vegetable soils in Nanjing, east China, were analyzed using gas chromatography–mass spectrometry (GC–MS). The total PAE concentrations in the soils ranged widely from 0.15 to 9.68 mg kg−1 with a median value of 1.70 mg kg−1, and di-n-butyl phthalate (DnBP), bis-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) were the most abundant phthalate esters. Soil PAE concentrations depended on the mode of use of plastic film in which PAEs were incorporated as plasticizing agents and both the plastic film and poultry manure appeared to be important sources of soil PAEs. Vegetables in rotation with flooded rice led to lower concentrations of PAEs in soil. The results indicate that agricultural plastic film can be an important source of soil PAE contamination and further research is required to fully elucidate the mechanisms of PAE contamination of intensive agricultural soils with different use modes of use of plastic film.
Показать больше [+] Меньше [-]Occurrence and distribution of heavy metals and tetracyclines in agricultural soils after typical land use change in east China
2013
Wu, Longhhua | Pan, Xia | Chen, Like | Huang, Yujuan | Teng, Ying | Luo, Yongming | Christie, Peter
Land use in east China tends to change from paddy rice to vegetables or other high-value cash crops, resulting in high input rates of organic manures and increased risk of contamination with both heavy metals (HMs) and antibiotics. This investigation was conducted to determine the accumulation, distribution and risks of HMs and tetracyclines (TCs) in surface soils and profiles receiving different amounts of farmyard manure. Soil samples collected from suburbs of Hangzhou city, Zhejiang province were introduced to represent three types of land use change from paddy rice to asparagus production, vineyards and field mustard cultivation, and divided into two portions, one of which was air-dried and sieved through 2-, 0.3- and 0.149-mm nylon mesh for determination of pH and heavy metals. The other portion was frozen at -20 °C, freeze-dried and sieved through a 0.3-mm nylon mesh for tetracyline determination. HM and TC concentrations in surface soils of 14-year-old mustard fields were the highest with total Cu, Zn, Cd and ∑TCs of 50.5, 196, 1.03 mg kg(-1) and 22.9 μg kg(-1), respectively, on average. The total Cu sequence was field mustard > vineyards > asparagus when duration of land use change was considered; oxytetracycline (OTC) and doxycycline were dominant in soils used for asparagus production; OTC was dominant in vineyards and chlortetracycline (CTC) was dominant in mustard soils. There were positive pollution relationships among Cu, Zn and ∑TCs, especially between Cu and Zn or Cu and ∑TCs. Repeated and excessive application of manures from intensive farming systems may produce combined contamination with HMs and TCs which were found in the top 20 cm of the arable soil profiles and also extended to 20-40 cm depth. Increasing manure application rate and cultivation time led to continuing increases in residue concentrations and movement down the soil profile.
Показать больше [+] Меньше [-]Perfluorinated alkylated substances in vegetables collected in four European countries; occurrence and human exposure estimations
2013
Herzke, Dorte | Huber, Sandra | Bervoets, Lieven | D’Hollander, Wendy | Hajslova, Jana | Pulkrabova, Jana | Brambilla, Gianfranco | De Filippis, Stefania Paola | Klenow, Stefanie | Heinemeyer, Gerhard | Voogt, Pim de
The human diet is recognised as one possible major exposure route to the overall perfluorinated alkylated substances (PFAS) burden of the human population, resulting directly from contamination of dietary food items, as well as migration of PFAS from food packaging or cookware. Most European countries carry out national monitoring programs (food basket studies) to monitor contamination with pollutants. Usually, for PFASs, non-coordinated approaches are used in Europe, since food basket studies are mainly carried out by national authorities following national requirements and questions, making comparisons between different countries difficult. A harmonised sampling campaign collecting similar food items in a uniform procedure enabling direct comparison between different regions in Europe was designed. We selected four countries (Belgium, Czech Republic, Italy and Norway), representing the four regions of Europe: West, East, South and North. In spring 2010 and 2011, 20 different types of vegetables were sampled in Belgium, Czech Republic, Italy and Norway. Perfluorinated carboxylic acids (PFCAs) were the main group of detected PFASs, with perfluorinated octanoic acid (PFOA) as the most abundant PFCA (with exception of samples from Czech Republic), followed by perfluorinated hexanoic acid and perfluorinated nonanoic acid. Dietary intake estimates for PFOA show only low human exposure due to vegetable consumption for adults and children, mostly governed by high intake of potatoes.
Показать больше [+] Меньше [-]Study on the photodegradation of amidosulfuron in aqueous solutions by LC-MS/MS
2013
Benzi, M. | Robotti, E. | Gianotti, V.
Sulfonylurea herbicides are extensively widespread for the protection of a variety of crops and vegetables because of their low application rates, high selectivity and low persistency in the environment; unfortunately, their low persistence does not always correspond to a lower toxicity, since new species potentially more toxic and stable than the precursor herbicides can form, owing to natural degradation processes. Here, the photodegradation of amidosulfuron in aqueous solutions was studied by high-performance liquid chromatography with diode array detection and tandem mass spectrometry to identify the degradation products in order to outline the environmental fate of the molecules generating from the simulation of one of the natural processes that can occur, i.e., photoinduced degradation. The photodegradation process results in a first order kinetic reaction with a t₁/₂value of 276 h (11.5 days) and a kinetic constant of 0.0027 h⁻¹, and three possible degradation products were identified. The results obtained are then compared to those obtained in previous works carried out in comparable experimental conditions about nicosulfuron and tribenuron-methyl, two sulfonylurea herbicides belonging to different classes, and to literature data: hypotheses on the existence of preferential degradation pathways are then drawn, in consequence of the molecular structure of the sulfonylurea pesticide. In particular, the use of organic solvents to obtain complete solubilization of the sample plays a fundamental role and deeply influences the degradation processes that, therefore, not always fully adhere to the actual natural photodegradation pathways. Moreover, considerations about toxicity were driven since the complete mineralisation of the sample is not reached: even when the parent pesticides are totally degraded, they are, however, transformed into other organic compounds showing, if subject to ecotoxicological tests, at least the same toxicity of the precursor herbicides. The evidence here presented suggests that, at least for the class of sulfonylurea pesticides, their professed low persistence actually does not produce any real advantage.
Показать больше [+] Меньше [-]Environmental factors and unhealthy lifestyle influence oxidative stress in humans—an overview
2013
Aseervatham, G Smilin Bell | Sivasudha, T. | Jeyadevi, R. | Arul Ananth, D.
Oxygen is the most essential molecule for life; since it is a strong oxidizing agent, it can aggravate the damage within the cell by a series of oxidative events including the generation of free radicals. Antioxidative agents are the only defense mechanism to neutralize these free radicals. Free radicals are not only generated internally in our body system but also trough external sources like environmental pollution, toxic metals, cigarette smoke, pesticides, etc., which add damage to our body system. Inhaling these toxic chemicals in the environment has become unavoidable in modern civilization. Antioxidants of plant origin with free radical scavenging properties could have great importance as therapeutic agents in several diseases caused by environmental pollution. This review summarizes the generation of reactive oxygen species and damage to cells by exposure to external factors, unhealthy lifestyle, and role of herbal plants in scavenging these reactive oxygen species.
Показать больше [+] Меньше [-]Perfluoroalkyl substances (PFASs) in food and water from Faroe Islands
2013
Diet and drinking water are suggested to be major exposure pathways for perfluoroalkyl substances (PFASs). In this study, food items and water from Faroe Islands sampled in 2011/2012 were analyzed for 11 perfluoroalkyl carboxylic acids (PFCAs) and 4 perfluoroalkane sulfonic acids (PFSAs). The food samples included milk, yoghurt, crème fraiche, potatoes, fish, and fish feed, and the water samples included surface water and purified drinking water. In total, nine PFCAs and four PFSAs were detected. Generally, the levels of PFAS were in the lower picogram per gram range. Perfluorobutanoic acid was a major contributor to the total PFASs concentration in water samples and had a mean concentration of 750 pg/L. Perfluoroundecanoic acid (PFUnDA) was predominating in milk and wild fish with mean concentrations of 170 pg/g. Perfluorooctane sulfonic acid (PFOS) was most frequently detected in food items followed by PFUnDA, perfluorononanoic acid, and perfluorooctanoic acid (PFOA). Levels of PFUnDA and PFOA exceeded those of PFOS in milk and fish samples. Prevalence of long-chain PFCAs in Faroese food items and water is confirming earlier observations of their increase in Arctic biota. Predominance of short-chain and long-chain homologues indicates exposure from PFOS and PFOA replacement compounds.
Показать больше [+] Меньше [-]