Ecological Risks Of Antibiotics Research Articles

Occurrence, Distribution, and Ecological Risk of Antibiotics in Surface Water in the Liaohe River Basin, China

The pollution and ecological risk characteristics of five typical antibiotics found in the surface water of the Liaohe River Basin (LRB) were analyzed and evaluated using solid-phase extraction and high-performance liquid chromatography tandem mass spectrometry. These results showed that macrolides have the highest average concentration of all antibiotics in the surface water of the LRB of 201.88 ng·L-1, followed by quinolones, trimethoprim, and sulfonamides with average concentrations of 113.40 ng·L-1, 93.93 ng·L-1, and 124.27 ng·L-1, respectively. Tetracycline demonstrated the lowest concentration at 24.37 ng·L-1. In addition, antibiotics pollution of the Daliao River is clearly identified as being higher than that of the Liaohe River, and the highest proportion of antibiotic pollution (49.1%) is found to come from human use according to a source apportionme0nt analysis. Relatively high levels of ecological risk are identified from Trimethoprim and Erythromycin-H2O concentrations, especially for cities such as Xinmin, Shenyang, and Anshan. The risk assessment indicates that surface water of the LRB faces high ecological risk and argues for greater attention to be paid to risk management and pollution controls.

Occurrence, Distribution and Ecological Risk of Aantibiotics in Surface Water of the Gonghu Bay, Taihu Lake

In order to assess the contamination degree and ecological risk of antibiotics in Gonghu Bay, Taihu Lake, the contamination characteristics of four kinds of antibiotics (tetracycline, quinolones, sulfonamides and macrolides) in surface water of the Gonghu Bay were analyzed using high performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS). The results showed that 13 of the 16 target antibiotics were detected in the Gonghu Bay. The mass concentrations of the 13 antibiotics ranged 0.005-4.720 μg·L-1, and OTC was of the highest concentration. The detection level of antibiotics was also different between the northern and the southern parts of Gonghu Bay, and the mass concentration of tetracycline in the northern part was higher than that in the southern part. Moreover, the concentrations of quinolones and sulfonamides in the southern part were larger than those in the northern part. The potential ecological risks of the detected antibiotics were assessed via using the risk quotients (RQs) approach. The preliminary results showed that 5 kinds of antibiotics: OTC, NOR, OFL, CIP and ENR were at high risk, accounting for 38.5% and 4 kinds of antibiotics TC, CTC, ROX and SMX were at medium risk, accounting for 30.8% in the antibiotics detected in Gonghu Bay, while the others (SMR, SMP, SQX, TMP) were at low risk. Ecological risk assessment revealed that some risks were present in antibiotics in the Gonghu Bay. The tetracyclines and quinolones were particularly prominent, which should be drawn enough attention, and corresponding preventive measures should be taken as well.

Occurrence, spatiotemporal distribution, mass balance and ecological risks of antibiotics in subtropical shallow Lake Taihu, China.

The objective of this study was to evaluate the occurrence, spatiotemporal distribution, mass balance and ecological risks of 43 commonly used human and veterinary antibiotics in both aqueous and sedimentary phases in a large subtropical shallow lake, Lake Taihu. In the aqueous phase, sulfonamides (2.64-344 ng L(-1)), lincomycin (ND to 53.8 ng L(-1)) and florfenicol (0.15-963 ng L(-1)) were the main compounds with high concentrations and detection frequencies. In the sedimentary phase, fluoroquinolones (ND to 174 ng g(-1), dry weight) and tetracyclines (ND to 39.6 ng g(-1), dry weight) were the predominant compounds. Antibiotic concentrations in Lake Taihu were generally lower relative to data documented in previous studies on China and other countries. The composition of antibiotics showed that livestock wastewater might be the main source of antibiotics in Lake Taihu, followed by domestic wastewater. Antibiotics in the lake water showed slight spatial variation in summer and significant spatial variation in winter; whereas, antibiotic concentrations in the sediments varied obviously, with high concentrations found in the sites close to potential pollution sources. Mass balance showed that sediments are an important sink and potential source for fluoroquinolones and tetracyclines. In addition to antibiotics' physicochemical properties, the spatiotemporal distribution of antibiotics in the lake was influenced by both pollution sources and lake hydrodynamics. The environmental risk assessment results showed that sulfamethoxazole could pose high risks on the algae in the aquatic ecosystem, followed by tetracyclines (algae) and fluoroquinolones (bacteria). Overall, our study reveals complex compositions and clear spatiotemporal dynamics in Lake Taihu, which were the consequence of pollution sources and lake hydrodynamics.

Effects of dissolved organic matter and coordination with Cu(II) on the phototransformation of sulfamethazine in aqueous solutions

Sulfonamide antibiotics (SAs) are well-acknowledged micropollutants in the aquatic environment at concentrations as high as μg/L. SAs are of acute concern because they can trigger an increase of resistant bacteria and accelerate the development of antibiotic resistance genes. Phototransformation plays an important role in the degradation of antibiotics in surface waters, and influences the fate and ecological risks of antibiotics. The photochemical behavior of antibiotics was obviously impacted by water constituents. However, water constituents and their interactions with metal ions on antibiotics photodegradation are still unclear. In this study, sulfamethazine (SMZ) was selected as target compound due to its wide usage in aquaculture and livestock operations. The effects of dissolved organic matter (DOM) and its coordination with Cu(II) on SMZ photodegradation were investigated. Results show that excited triplet state DOM (3DOM*) is largely responsible for the photolytic enhancement of SMZ in the presence of DOM and the reaction mechanism is identified as electron transfer followed proton transfer from SMZ to 3DOM*. Additionally, the photogenerated ·OH was found in the Cu(II)-DOM system, which promoted the photodegradation of SMZ.

Distribution and ecological risk of antibiotics in a typical effluent–receiving river (Wangyang River) in north China

In this study, the occurrence and distribution of sixteen antibiotics belonging to four groups in surface water, sediment and groundwater samples from the Wangyang River (WYR), a typical river receiving sewage discharges were investigated. Laboratory analyses revealed that antibiotics were widely distributed in the studied area. The aqueous samples were unavoidably contaminated with antibiotics, and the target antibiotics present in high levels were oxytetracycline, tetracycline, chlortetracycline, ofloxacin, sulfamethoxazole, and trimethoprim, with maximum concentrations of the individual contaminant at 3.6×105, 9.7×103, 6.9×104, 1.2×104, 4.8×103, and 1.1×103ngL−1, respectively. Oxytetracycline, tetracycline, ciprofloxacin and roxithromycin were the most frequently detected compounds in sediment samples, with maximum concentrations of the individual contaminant at 1.6×105, 1.7×104, 2.1×103 and 2.5×103ngg−1, respectively. The results also revealed that the high intensity of aquaculture activities could contribute to the increasing levels of antibiotics in the area. According to the ratios of measured environmental concentration (MEC) to predicted no-effect concentration (PNEC), chlortetracycline, tetracycline, ofloxacin, ciprofloxacin, erythromycin-H2O and sulfamethoxazole may present possible environmental risk to Pseudokirchneriella subcapitata, Synechococcus leopoliensis and M. aeruginosa. Attention should be given to the long-term ecological effects caused by the continuous discharge of antibiotics in the WYR area.

Occurrence, fate, and ecotoxicity of antibiotics in agro-ecosystems. A review

Globally, besides human medicine, an increasing amount of antibiotics as veterinary drugs and feed additives are used annually in many countries with the rapid development of the breeding industry (livestock breeding and aquaculture). As a result, mostly ingested antibiotic doses (30–90%) and their metabolites to humans and animals, as emerging persistent contaminants, were excreted together with urine and feces, and subsequently disseminated into environmental compartments in forms of urban wastewater, biosolids, and manures. More importantly, significant amount of antibiotics and their bioactive metabolites or degradation products were introduced in agro-ecosystems through fertilization and irrigation with antibiotics-polluted manures, biosolids, sewage sludge, sediments, and water. Subsequently, accumulation and transport of antibiotics in soil–crop systems, particularly soil–vegetable systems, e.g., protected vegetable and organic vegetable production systems, poses great risks on crops, soil ecosystem, and quality of groundwater- and plant-based products. The aim of this review is to explore the sources, fates (degradation, adsorption, runoff, leaching, and crop uptake), and ecological risks of antibiotics in agro-ecosystems and possible food security and public health impacts. Three topics were discussed: (1) the occurrence, fates, and ecological impacts of antibiotics in agro-ecosystems, a global agro-ecological issue; (2) the potential ecological risks and public health threat of antibiotic pollution in soil–vegetable system, especially protected vegetable and organic vegetable production systems; and (3) the strategies of reducing the introduction, accumulation, and ecological risks of antibiotics in agro-ecosystems. To summarize, environmental contamination of antibiotics has become increasingly serious worldwide, which poses great risks in agro-ecosystems. Notably, protected vegetable and organic vegetable production systems, as public health closely related agro-ecosystems, are susceptible to antibiotic contamination. Occurrence, fate, and ecotoxicity of antibiotics in agro-ecosystems, therefore, have become most urgent issues among antibiotic environmental problems. Nowadays, source control, including reducing use and lowering environmental release through pretreatments of urban wastes and manures is a feasible way to alleviate negative impacts of antibiotics in agro-ecosystems.