Temperature-dependent chemical toxicity has become a crucial issue taking into consideration that lakes, especially shallow waterbodies, are impacted by climate change worldwide. In this study, we are looking for an answer to what extent standard ecotoxicity assays being performed under constant and relatively low temperatures are capable of predicting the chemical risk posed by pesticides. Lemna minor test plants were exposed to glyphosate in concentrations in the range of 25, 50, 100, 200, and 400 μg/L at temperatures 10, 15, 20, 25, 30, and 35 °C. Two peaks appeared when growth inhibition was assessed; lower concentrations elucidated higher inhibition, at 20 °C, while higher concentrations were found at a higher temperature of 30 °C. The toxic effect experienced at 20 °C indicates that reported PNEC values cannot be sufficient to protect non-target aquatic species in certain environmental scenarios. In addition to growth inhibition, phytotoxicity was also assessed based on peroxidase (POD) concentrations. In general, POD showed greater sensitivity, already showing a response at the lowest temperature tested, 10 °C. Decreased POD activity was detected in the temperature range of 10–30 °C, most probably indicating damage to cell and plasma membranes.
Urban gardening has become more and more popular in recent years, as people might prefer to grow their own vegetables from controlled sources. In addition, community building also plays a key role. However, air pollution in settlements is a serious hazard affecting the quality of home-grown vegetables. During the vegetation period, traffic is the main factor generating atmospheric particulate matter. These particles will, in turn, bind to potentially toxic compounds, of which heavy metals and polycyclic aromatic hydrocarbons (PAHs) are the most widely studied and discussed. In addition to their potential toxicity, both groups contain carcinogenic species. Heavy metals, as well as PAHs, are capable of bioaccumulation, depending on the element or compound’s characteristics and the vegetable species. Some leafy vegetables can accumulate these toxic materials in significant quantities. As dietary uptake is considered the major exposure route of both heavy metals and PAHs, the consumption of impacted vegetables might even pose human health risks. This recent review summarises available data reported on heavy metal and PAH accumulation in urban environments, specified by vegetable species. Also, the assessment of possible human impact is given.
Open burning of agricultural waste is a common practice in both developed and developing regions of the world, and the emissions pose serious inputs for ambient concentrations of atmospheric particulate matter (PM). In addition, when agricultural waste burning is combined with open-air burning of domestic waste such as plastic, rags, or tires, the potential risk of generating toxic emissions increases. PM samples produced via controlled burning of selected waste types were tested in our laboratory using the No. 227 OECD Guideline for the Testing of Chemicals: Terrestrial Plant Test. Comparing two recommended test species, lettuce (Lactuca sativa) and mustard (Sinapis alba), L. sativa showed significantly higher sensitivity, as treatment elucidated biomass reduction (Df = 1, F = 16.43, p = 0.000385), the biomass of the treated plants was 61.4-91.7% of the control plants. In our investigation inhibition in photosynthetic pigment activity chlorophyll-b in lettuce (Df = 1, F = 3.609, p = 0.0701) was found. The levels of the stress enzyme peroxidase increased significantly in the case of both test species (L. sativa: Df = 1, F = 6.76, p = 0.0112; S. alba: Df = 1, F = 49.99, p = 1.63 × 10−9), indicating that peroxidase could be regarded as the most sensitive indicator of air pollution. The bioaccumulation pattern was also assessed, proving the risk of significant bioaccumulation of potentially toxic compounds in edible parts of the vegetables tested. Both test plants accumulated higher molecular weight PAHs in significant quantities, as the concentration of 5-ring PAHs was 43.2 μg/kg in mustard and 49.35 μg/kg in lettuce.
Wet deposition of atmospheric polycyclic aromatic hydrocarbons (PAHs) is considered an important source of these potentially toxic compounds in soils. In addition to affecting soil quality, they might be taken up by higher plants, potentially causing phytotoxicity or being accumulated in various organs. Plants are exposed to atmospheric PAHs via the aerial parts and via the soil-root system. The primary aim of this study was to present an experimental setup which can be properly used to quantify PAH accumulation investigating both potential pathways. Rocket (Eruca sativa Mill.) was selected as the model species. The test was conducted following the No. 227 OECD Vegetative Vigor Test. Plants were sprayed with the extract of particles generated during the operation of a diesel-powered vehicle simulating the air–aerial parts–root pathway, while the same extract was used to treat the soil simulating the soil–root–aerial parts pathway. In the soil–root–stem–leaf pathway, the total PAH concentration was 108 μg/kg in the soil, 143 μg/kg in the roots, 92.3 μg/kg in the stems, and 62.5 μg/kg in the leaves. Results showed that higher molecular weight PAHs were mostly accumulated in the roots, but their transfer to above-ground parts cannot be excluded. This study supports the importance of wet deposition in transferring atmospheric PAHs to soils.
Atmospheric particulate matter poses a high risk by carrying potentially toxic components such as polycyclic aromatic hydrocarbons (PAHs). The major sources of these potentially toxic compounds include traffic-related emissions and winter heating, implying the combustion of fossil fuels or biomass. Air pollution, especially chronic exposure, poses the most serious human health hazard in childhood, and several studies emphasise the importance of research on the potential impacts of air pollution in school environments. While indoor air quality studies are already available in Hungary, investigations on outdoor air pollution in school environments are missing. To fill this gap, in a medium-sized Hungarian town, Veszprém, six schools were selected to assess air quality in the outdoor environments where schoolchildren spend their breaks and have physical training. These schools represent different locations and conditions, from high-trafficked sites to suburban environments. Using resuspended dust samples, environmental quality was assessed based on PAH contents of the samples and ecotoxicity tests (Vibrio fischeri bacterial bioassay). Ecotoxicity of the samples moved in a wide range, from highly toxic to non-toxic. PAH measurements indicated considerable contamination in the case of one sample taken from a suburban area. Source apportionment demonstrated that winter heating is also an important pollution source.