Accumulation of heavy metals in water, sediments and wetland plants of kizilirmak delta (samsun, Turkey)

Contaminants of emerging concern in urine: a review of analytical methods for determining diisocyanates, benzotriazoles, benzothiazoles, 4-methylbenzylidene camphor, isothiazolinones, fragrances, and non-phthalate plasticizers

Human biomonitoring (HBM) frameworks assess human exposure to hazardous chemicals. In this review, we discuss and summarize sample preparation procedures and analytical methodology for six groups of chemicals of emerging concern (CECs), namely diisocyanates, benzotriazoles, benzothiazoles, 4-methylbenzylidene camphor, isothiazolinones, fragrances, and non-phthalate plasticizers, which are increasingly detected in urine, however, are not yet widely included in HBM schemes, despite posing a risk to human health. The sample preparation procedures depend largely on the chemical group; however, solid-phase extraction (SPE) is most often used due to the minimized sample handling, lower sample volume, and generally achieving lower limits of quantification (LOQs) compared to other extraction techniques. In terms of sample analysis, LC-based methods generally achieve lower limits of quantification (LOQs) compared to GC-based methods for the selected six groups of chemicals owing to their broader chemical coverage. In conclusion, since these chemicals are expected to be more frequently included in future HBM studies, it becomes evident that there is a pressing need for rigorous quality assurance programs to ensure better comparability of data. These programs should include the reporting of measurement uncertainty and facilitate inter-laboratory comparisons among the reporting laboratories. In addition, high-resolution mass spectrometry should be more commonly employed to enhance the specificity and selectivity of the applied analytical methodology since it is underrepresented in HBM. Furthermore, due to the scarcity of data on the levels of these CECs in urine, large population HBM studies are necessary to gain a deeper understanding of the associated risks.

Heavy metal resistance of marine bacteria on the sediments of the Black Sea

The Black Sea is unfortunately globally established as a highly polluted sea, with contaminants from various sources polluting its marine sediments. This study aimed at analyzing heavy metal resistance levels by heterotrophic bacteria colonizing marine sediments across Black Sea shores within Turkey. Twenty-nine bacterial samples from marine sediments were investigated through exposure to sixteen heavy metal salts using the microdilution method. The minimum inhibitory concentration values for bacterial colonies within such marine sediment samples ranged from <0.97 mM/L to >1000 mM/L. Trough and peak minimum inhibitory concentration values were determined at <0.17 mg/mL and > 331 mg/mL. Peak tolerated and peak toxic heavy metals were identified as iron and cadmium, respectively. Resistance ratios were also obtained in this study. Bacillus wiedmannii was identified as the most resistant bacterial population when exposed to heavy metal salts. This study shows occurrence of heavy metal resistant bacteria within Black Sea sediments.

Heavy Metal Accumulation in Water, Soil, and Plants of Municipal Solid Waste Landfill in Vientiane, Laos

The municipal solid waste (MSW) landfill in Vientiane, Laos, which receives > 300 tons of waste daily, of which approximately 50% is organic matter, has caused serious environmental problems. This study was conducted to investigate the accumulated levels of heavy metals (HMs) (cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn)) in water (surface and groundwater), soil, and plants between dry and wet seasons according to the standards of the Agreement on the National Environmental Standards of Laos (ANESs), Dutch Pollutant Standards (DPSs), and the World Health Organization (WHO), respectively. Although no impact of pollution on the surface water was observed, the levels of Cr and Pb in the groundwater significantly exceeded the basics of ANESs and WHO in both seasons. The pollution caused by Cd and Cu reached the eco-toxicological risk level in the landfill soils and its vicinity. The vegetable Ipomoea aquatica, which is consumed by the nearby villagers, was seriously contaminated by Cr, Pb, Cu, and Zn, as the accumulation of these toxic metals was elevated to much greater levels as compared to the WHO standards. For the grass Pennisetum purpureum (elephant grass), the quantities of HMs in all plant parts were extreme, perhaps due to the deeper growth of its rhizome than I. aquatica. This study is the first to warn of serious HM pollution occurring in the water, soil, and plants in the MSW landfill of Vientiane, Laos, which requires urgent phytoremediation. The indication of what sources from the MSW principally cause the pollution of HMs is needed to help reduce the toxicological risks on Lao residents and the environment in Vientiane as well.

Presence of pharmaceuticals and heavy metals in the waters of a Mediterranean coastal wetland: Potential interactions and the influence of the environment

The occurrence of 17 relevant pharmaceuticals and 7 heavy metals in the waters of the Pego-Oliva Marsh Natural Park (Valencia Community, Spain) were monitored. Thirty four zones (including the lagoon and the most important irrigation channels), covering the main land uses and water sources, were selected for sampling. Thirty three of them were contaminated with at least one pharmaceutical. Ibuprofen and codeine were the pharmaceuticals more frequently detected, in concentrations between 4.8 and 1.2 ng/L and a maximum of 59 ng/L and 63 ng/L, respectively. Regarding metals, Zn showed values under the detection limit in all the samples, while Cd, Co, Cr, Cu, Ni and Pb were detected at concentrations lower than the WHO and EU maximum levels for drinking waters. Ni showed significant direct correlations with diazepam, norfloxacin, ofloxacin and fenofibrate, and inverse relationships with ibuprofen, at 99 and 95% of significance. Cu, Co and Cr also showed significant correlations with some of the pharmaceuticals. These interactions could favor the synergistic/antagonistic interactions among pharmaceuticals and metals in the marsh, which can affect its aquatic fauna and flora or even human health. The influences of the water sources, land uses and spatial distribution of both types of contaminants were also studied.