Assessment of the impact of pharmaceutical residues on living organisms is a very complex subject. Apart from taking into account the toxicity of individual compounds, environmental factors should also be taken into account. In this paper, attempts were made to assess the impact of coexisting inorganic ions and changes in pH on the toxicity of ten selected pharmaceuticals. Two bioassays were used to measure the estrogenic and androgenic effects (XenoScreen YES/YAS – Saccharomyces cerevisiae) and acute toxicity (Microtox® – Vibrio fischeri).The Microtox® test gave the most definitive outputs concerning the determination of interaction type between drugs and chemical species. Synergism was proven for almost all drugs and chemical species, and only two cases of antagonism were found. Significant drug/pH interactions were rare.Regarding the XenoScreen YES/YAS bioassay, when estrogenic and androgenic agonistic effects (YES+ and YAS+, respectively) were studied, many cases of well-expressed synergism for all inorganic ions with limited number of drugs (diazepam, fluoxetine, estrone, chloramphenicol for the YES+ test and diazepam, progesterone, androstenedione, and estrone for the YAS+ test) were found. Antagonism was also proven for the YES+ test, especially for diclofenac and androstenedione interacting with cations. On the other hand, the YES- and YAS- tests (estrogenic and androgenic, respectively, antagonistic effects) did not indicate cases of synergetic interaction except for the couples Br−/diazepam and NH4+/ketoprofen. Antagonistic drug/ion interactions were detected only with diclofenac and fluoxetine. It is interesting that well-expressed (antagonism or synergism) drug/pH interactions were rare.Both tests were found utilizable in performing studies on impact of ions/pH fluctuations on drugs mixtures' toxicity confirming in most cases synergic impact of parameters studied on toxicity. The approach proposed in the paper seems to be proven as a reliable tool in assessing impact of abiotic factors on toxicity and endocrine potential of complex mixtures of pharmaceuticals' mixtures.

The combination of emerging antibiotic resistance and lack of discovery of new antibiotic classes poses a threat to future human welfare. Antibiotics are administered to livestock at a large scale and these may enter the environment by the spreading of manure on agricultural fields. They may leach to groundwater, especially in the Netherlands which has some of the most intensive livestock farming and corresponding excessive manure spreading in the world. This study investigates the presence of antibiotics in groundwater in two regions with the most intensive livestock farming in the Netherlands. If so, the hydrochemical conditions were further elaborated. Ten multi-level wells with in total 46 filters were sampled, focusing on relatively young, previously age-dated groundwater below agricultural fields. Twenty-two antibiotics were analyzed belonging to the following antibiotic groups: tetracyclines, sulfonamides, trimethoprims, β-lactams, macrolides, lincosamides, quinolones, nitrofurans and chloramphenicol. The samples were analyzed for these antibiotics by LC-MS/MS ESI-POS/NEG (MRM) preceded by solid phase extraction which resulted in importantly low detection limits. Six antibiotics were found above detection limits in 31 filters in seven wells: sulfamethazine, sulfamethoxazole, lincomycin, chloramphenicol, ciprofloxacin, and sulfadiazine. The concentrations range from 0.3 to 18 ng L−1. Sulfonamides were detected at all measured depths down to 23 meters below surface level with apparent groundwater ages up to 40 years old. No antibiotics were detected below the nitrate/iron redox cline, which suggests that the antibiotics might undergo degradation or attenuation under nitrate-reducing redox conditions. This study provides proof that antibiotics are present in groundwater below agricultural areas in the Netherlands due to the spreading of animal manure.

Groundwater is an essential public and drinking water supply and its protection is a goal for global policies. Here, we investigated the presence and prevalence of antibiotic residues, antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and microbial contamination in groundwater environments at various distances from urban areas. Antibiotic concentrations ranged from below detection limit to 917 ng/L, being trimethoprim, macrolide, and sulfonamide the most abundant antibiotic classes. A total of eleven ARGs (aminoglycoside, β-lactam, chloramphenicol, Macrolide-Lincosamide-Streptogramin B - MLSB, sulfonamide, and tetracycline), one antiseptic resistance gene, and two MGEs were detected by qPCR with relative abundances ranging from 6.61 × 10−7 to 2.30 × 10−1 copies/16S rRNA gene copies. ARGs and MGEs were widespread in the investigated groundwater environments, with increased abundances not only in urban, but also in remote areas. Distinct bacterial community profiles were observed, with a higher prevalence of Betaproteobacteria and Bacteroidetes in the less-impacted areas, and that of Firmicutes in the contaminated groundwater. The combined characteristics of increased species diversity, distinct phylogenetic composition, and the possible presence of fecal and/or pathogenic bacteria could indicate different types of contamination. Significant correlations between ARGs, MGEs and specific taxa within the groundwater bacterial community were identified, revealing the potential hosts of resistance types. Although no universal marker gene could be determined, a co-selection of int1, qacEΔ1 and sulI genes, a proxy group for anthropogenic pollution, with the tetC, tetO, tetW resistance genes was identified. As the tet group was observed to follow the pattern of environmental contamination for the groundwater samples investigated in this study, our results strongly support the proposal of this group of genes as an environmental tracer of human impact. Overall, the present study investigated several emerging contaminants in groundwater habitats that may be included in monitoring programs to enable further regulatory and protection measures.

This study highlights an efficient sample pre-treatment method for preconcentration and detection of chloramphenicol in marine water using molecularly imprinted solid-phase extraction (MISPE). Chloramphenicol molecularly imprinted microspheres were prepared and evaluated on the base of morphology, capacity and selectivity. The imprinted microspheres exhibited specific recognition and high retention capability to chloramphenicol and were applied as special solid-phase extraction adsorbents. An off-line MISPE protocol has been optimized and a creative analytical method coupled to HPLC-DAD was successfully developed for the cleanup and determination of chloramphenicol in seawater samples. Method performance was satisfactory with recoveries ranging from 81 to 90% and relative standard deviation (RSD) was <4.93% (n = 3). Accuracy of the method was assessed at three spiking concentration levels and the limit of detection was 5 ng L⁻¹. Finally, five seawater samples from Jiaozhou Bay of China were determined and the results showed that there was no chloramphenicol detected.

The aim of this study was to assess the toxicological potential of binary drug mixtures and individual drugs under different pH conditions with different inorganic ion additions on the germination of Sorghum bicolor (sorgo) seeds. To assess whether the given drug mixtures were more phytotoxic than the individual compounds, concentration addition (CA) and independent action (IA) approaches were applied to estimate the predicted phytotoxicity values, followed by calculations of the MDR (model deviation factor) to determine the deviation from the predicted values. Binary mixtures of chloramphenicol with ketoprofen, diclofenac sodium, and oxytetracycline hydrochloride proved to be synergistic. The pH changes had the largest impact on the phytotoxicity of the diclofenac sodium and ketoprofen solutions, elevating their toxicity toward S. bicolor, and the co-presence of inorganic ions was shown to have an impact on ketoprofen, chloramphenicol, and oxytetracycline hydrochloride. Most of the interactions between sorgo plants and pharmaceuticals with added ions were antagonistic in nature, particularly those calculated using the IA model, with a few cases (one case for ketoprofen and chloramphenicol, two cases for oxytetracycline hydrochloride, and four cases for diclofenac sodium) of overestimation.

The concentration of certain heavy metals in various foods (fruits, cereals, legumes, and bee products) produced in industrial and urban cities is increasing each year following industrial development. Quality of honey and its contamination by different polluting agents are related essentially to its production environment, or it can arise from beekeeping practices. In the present study, the determination of physicochemical properties: moisture, pH, total acidity, electric conductivity, hydroxymethylfurfural (HMF), sugars, and chloramphenicol (CAP) residues; the metal content by determination of two toxic metals levels: lead (Pb) and cadmium (Cd); and other trace elements: magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), and nickel (Ni) in 23 different honey samples collected from North regions of Algeria were investigated. The physicochemical properties and the metal contents were found within the ranges established by the international standards. For the antibiotic residues, only four honey samples are contaminated by CAP. Metals were found in non-significant values and are in safety baseline levels for human consumption except Mg which exceed the limits. These results suggested that honey could be used as an indicator to detect contaminating agents from the environment since bees are excellent sentinels for assessing environmental contamination because of their physiological and biological characteristics.