Benzo[a]pyrene (BaP) is a hazardous compound for human health and for environmental compartments. Its transfer and deposition through the atmosphere affects soil quality. In this context, we quantified the content of BaP and other Polycyclic Aromatic Hydrocarbons (PAHs) in the soils of a prominent Coal Region in Transition to test whether the soil screening levels in force are realistic and whether they reflect the complexity of regions closely linked to heavy industries and mining. In this regard, soil screening levels are thresholds often established without considering historical anthropogenic activities that affect soil (diffuse pollution). The 150 soil samples studied showed a notable content of high molecular weight PAHs, and BaP surpassed the threshold levels in practically the entire area. PAH-parent diagrams revealed a relatively homogenous fingerprint of four clusters obtained in a multivariate statistical study. In addition, molecular diagnostic ratios pointed to coal combustion as the main pollution source, whereas only some outliers appeared to be related to specific spills. A BaP threshold was calculated to be 0.24 mg kg⁻¹, over 10 times the limit established in Spain. Finally, a factor analysis revealed a positive correlation of BaP with elements usually emitted in coal combustion processes, such as Tl and V. This observation fosters the hypothesis of a historical and indelible pollution fingerprint in soils whose sources, characteristics and potential environmental and health concerns deserve further attention. All things considered, caution should be taken when using soil screening levels in regions associated with coal exploitation and heavy industry.

While considerable efforts have been made to address the relationship between urbanization and environmental issues, few of them focus on household emissions. Thus, this work aimed at evaluating the effect of urbanization on household wastewater emissions, and made a distinction between the efficient- and the inefficient-emissions. We compiled a China’s provincial dataset over the period 2005–2017, and estimates indicated that a 1% rise in the urbanization was correlated with a 0.581 increase of efficient emissions, while inefficient emissions decreased by 7.606. As of 2017, the sample period end year, the inefficient emissions accounted for 10.5% of the total emissions of China as a whole, which was relatively large and could not be overlooked. Meanwhile, a back-of-the-envelope estimate revealed that urbanization had a negative impact on China’s total emissions, with a marginal effect ranging from −0.226 to −1.354 over the sample period. The above findings, however, did not imply that urbanization would spontaneously reduce the inefficient- and total-emissions. Thus, the government in the process of urbanization should strengthen environmental education, municipal facilities, and others.

The occurrence of Active Pharmaceutical Ingredients (APIs) in the environment is becoming a major area of concern due to their undesirable effects on non-target organisms. This study investigated the occurrence and risk of contamination by five antibiotics and three antiretrovirals drugs in a fast-growing peri-urban area in Kenya, with inadequate sewer system coverage. Due to poor sewage connectivity and poorly designed decentralized systems, wastewater is directly released in open drains. Water and sediment samples were collected from open surface water drains, while wastewater samples were collected from centralized wastewater treatment plants (WWTP). Solid-phase extraction and ultrasonic-assisted extraction for the aqueous and sediment samples respectively were carried out and extracts analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) using isotopically labeled internal standards. APIs were observed with the detection frequency ranging from 36% to 100%. High mean concentrations of 48.7 μg L⁻¹, 108 μg L⁻¹, and 532 μg L⁻¹ were observed in surface drains for Lamivudine (3 TC), Sulfamethoxazole (SMX), Ciprofloxacin (CIP) respectively. Drain sediments also showed high concentrations of APIs ranging from 2.1 to 13,100 μg kg⁻¹. APIs in this study exceeded those observed in existing literature studies. JKUAT WWTP removal efficiencies varied from −90.68% to 72.67%. Total APIs emission load of the study area was 3550 mg d⁻¹ with WWTP effluent contributing higher loads (2620 mg d⁻¹) than surface water drains (640 mg d⁻¹). Zidovudine (ZDV), nevirapine (NVP), and trimethoprim (TMP) loads in drains, however, exceeded WWTP effluent. Low to high ecotoxicity risk of the individual APIs were observed to the aquatic environment, with high risks for the development of antibiotic resistance in microbiome as determined by the risk quotient (RQ) approach. Risk management through efficient wastewater collection, conveyance, and treatment is necessary to suppress the measured concentrations.

Soil contaminants can cause direct harm to lizards due to their regular swallowing of soil particles. As the world’s fastest growing insecticide with long half-life in soil, the endocrine disrupting effect of neonicotinoids on lizards deserves more attention. In this report, we assessed the endocrine disrupting effect of imidacloprid on Eremias argus during 28 days of continuous exposure. Among the imidacloprid and its metabolites, only the metabolite 6-chloropyridic acid had a significant accumulation in the gonads and was positively correlated with its blood concentration. Imidacloprid might cause endocrine disrupting effects on lizards in two ways. First, the desnitro metabolites of imidacloprid could accumulate in the brain, inhibited the secretion of gonadotropin-releasing hormone, and ultimately affected the feedback regulation of hypothalamic-pituitary-gonadal related hormones. Secondly, imidacloprid severely inhibited the gene expression of the corresponding enzymes in the gonadal anti-oxidative stress system, causing histological damage to the gonads and ultimately affecting gonadal function. Specifically, exposure to imidacloprid resulted in abnormal arrangement of spermatogenic epithelial epithelium, hyperplasia of epididymal wall, and oligospermia of male lizard. Meanwhile, gene expressions of cyp17, cyp19, and hsd17β were severely inhibited in the imidacloprid exposure group, consistent with decreased levels of testosterone and estradiol in plasma. Imidacloprid exposure could cause insufficient androgen secretion and less spermatogenesis in male lizards. The risk of imidacloprid exposure to female lizards was not as severe as that of male lizards, but it still inhibited the expression of cyp19 in the ovaries and led to a decrease in the synthesis of estradiol. This study firstly reported the endocrine disruption of imidacloprid to lizards, providing new data for limiting the use of neonicotinoids.

In order to tackle China’s severe air pollution issue, the government has released the “Air Pollution Prevention and Control Action Plan” (known simply as the “Action Plan”) since 2013. A recent study reported a decreased trend in PM₂.₅ concentrations over 2013–2017, but O₃ pollution has become more serious. However, the effects of surface O₃ on crops are unclear after the implementation of the “Action Plan”. Here, we evaluated the potential negative effects of surface O₃ on three main food crops (winter wheat, maize and rice) across China during 2015–2018 using nationwide O₃ monitoring data and AOT40-yield response functions. Results suggested that mean O₃ concentration, AOT40 and relative yield loss in China showed an overall upward trend from 2015 to 2018. During winter wheat, maize, single rice, double-early rice, and double-late rice growing seasons, mean O₃ concentration in recent years ranged from 38.6 to 46.9 ppb, 40.2–43.9 ppb, 39.3–42.2 ppb, 33.8–40.0 ppb, and 35.9–39.1 ppb, respectively, and AOT40 mean values ranged from 8.5 to 14.3 ppm h, 10.5–13.4 ppm h, 9.8–11.9 ppm h, 5.2–9.2 ppm h, and 8.0–9.5 ppm h, respectively. O₃-induced yield reductions were estimated to range from 20.1 to 33.3% for winter wheat, 5.0–6.3% for maize, 7.3–8.8% for single rice, 3.9–6.8% for double-early rice and 5.9–7.1% for double-late rice. O₃-induced production losses for winter wheat, maize, single rice, double-early rice, and double-late rice totaled 39.5–88.2 million metric tons, 12.6–21.0 million metric tons, 9.5–11.3 million metric tons, 1.2–1.8 million metric tons, and 2.2–2.7 million metric tons, respectively, and the corresponding economic losses totaled 14.3–32.0 billion US$, 3.9–6.5 billion US$, 3.9–4.6 billion US$, 0.5–0.7 billion US$, and 0.9–1.1 billion US$, respectively. Our results suggested that the government should take effective measures to reduce O₃ pollution and its effects on agricultural production.

Marine oil spill often causes contamination of drinking water sources in coastal areas. As the use of oil dispersants has become one of the main practices in remediation of oil spill, the effect of oil dispersants on the treatment effectiveness remains unexplored. Specifically, little is known on the removal of dispersed oil from contaminated water using conventional adsorbents. This study investigated sorption behavior of three prototype activated charcoals (ACs) of different particle sizes (4–12, 12–20 and 100 mesh) for removal of dispersed oil hydrocarbons, and effects of two model oil dispersants (Corexit EC9500A and Corexit EC9527A). The oil content was measured as n-alkanes, polycyclic aromatic hydrocarbons (PAHs), and total petroleum hydrocarbons (TPHs). Characterization results showed that the smallest AC (PAC100) offered the highest BET surface area of 889 m2/g and pore volume of 0.95 cm3/g (pHPZC = 6.1). Sorption kinetic data revealed that all three ACs can efficiently adsorb Corexit EC9500A and oil dispersed by the two dispersants (DWAO-I and DWAO-II), and the adsorption capacity followed the trend: PAC100 > GAC12 × 20 > GAC4 × 12. Sorption isotherms confirmed PAC100 showed the highest adsorption capacity for dispersed oil in DWAO-I with a Freundlich KF value of 10.90 mg/g∙(L/mg)1/n (n = 1.38). Furthermore, the presence of Corexit EC9500A showed two contrasting effects on the oil sorption, i.e., adsolubilization and solubilization depending on the dispersant concentration. Increasing solution pH from 6.0 to 9.0 and salinity from 2 to 8 wt% showed only modest effect on the sorption. The results are useful for effective treatment of dispersed oil in contaminated water and for understanding roles of oil dispersants.

Accumulation and oral bioavailability of nickel (Ni) were rarely assessed for staple crops grown in high geogenic Ni soils. To assess exposure risk of geogenic Ni, soil, wheat, and rice samples were collected from a naturally high background Ni area and measured for Ni oral relative bioavailability (RBA, relative to NiSO₄) using a newly developed mouse urinary Ni excretion bioassay. Results showed that soils were enriched with Ni (80.5 ± 23.0 mg kg⁻¹, n = 58), while high Ni contents were observed in rice (2.66 ± 1.46 mg kg⁻¹) and wheat (1.32 ± 0.78 mg kg⁻¹) grains, with rice containing ∼2-fold higher Ni content than wheat. Ni-RBA was low in soil (14.8 ± 7.79%, n = 18), but high in wheat and rice with rice Ni-RBA (85.9 ± 19.1%, n = 9) being ∼2-fold higher than wheat (46.1 ± 21.2%, n = 16). A negative correlation (r = 0.61) was observed between Ni-RBA and iron content in rice and wheat, suggesting the low iron status of rice drives its high Ni bioavailability. The higher Ni accumulation and bioavailability for rice highlights that rice consumption was a more important contributor to daily Ni intake compared to wheat, while Ni intake from direct soil ingestion was negligible. This study suggests a potential health risk of staple crops especially rice when grown in high geogenic Ni areas.

We conducted the first comprehensive assessment of the presence, source, and ecotoxicological implication of 13 banned and restricted organochlorine pesticides (OCPs) in the surface water along the Ganga River for two different seasons. Surface water samples were collected along the 2525 km stretch of the Ganga through 43 sites representing five zones of diverse land-use pattern, pesticide consumption rate, and varied flow. The mean concentrations of ΣOCPs were significantly higher (∼2–5 times) in the post-monsoon or wet season [range: 0.126 to 10.402 μg/L (mean: 2.482 μg/L ± 3.589 and median: 1.433)] than in the post-winter or dry season [range: 0.053 to 3.010 μg/L (mean: 0.765 μg/L±1.033 and median: 0.399)]. Lindane (γ-HCH) was the dominant and most frequently detected pesticide at all the sites, indicating possible continued use of this banned pesticide in agricultural practices. The spatial distribution of OCPs revealed non-significant difference amongst different zones and indicate that point source pollution from the open drains along the Ganga could be responsible for observed trend. Ratio diagnostic analysis highlighted the fresh inputs and potential illegal use of lindane and chlordane at all the zones whereas, historical use of DDT was revealed at the majority of sites. Interestingly, fresh inputs of DDT were observed in the relatively pristine high altitude Upper zone (UZ) suggesting long-range atmospheric transfer and its continued use in the zone. Risk quotient (RQ) analysis revealed high ecotoxicological risks (>1), at all the studied sites for p, p’ DDE. The lower zone (LZ) emerged as a high ecological risk zone. The study highlights that though the OCPs analysed in this study are banned/restricted in India, still the implementation of the ban is poor and delayed and the country requires stricter adherence to its National Implementation Plan (NIP) on pesticides.

Goethite is a common iron hydroxide, which can be substituted by manganese (Mn) in the goethite structure. It is important to investigate the immobilization of uranium(VI) on Mn-substituted goethite (Mn-Goe) to understand the fate and migration of uranium in soils and sediments. In this study, the sorption of uranium(VI) by Mn-Goe was investigated as a function of pH, adsorbent dosage, contact time, and initial uranium concentration in batch experiments. Several material analysis techniques were used to characterize manganese substituted materials. Results indicated that Mn was successfully introduced into the goethite structure, the length of particles increased gradually, the surface clearly exhibited higher roughness with increasing Mn content, and that uranium(VI) sorption of synthetic Mn-Goe appeared to be higher than that of goethite. The sorption kinetics supported the results presented by the pseudo-second-order model. The sorption capacity of uranium on Mn-Goe was circa 77 mg g⁻¹ at pH = 4.0 and 25 °C. Fourier transform-infrared spectroscopy (FT-IR) analyses revealed that uranium ions were adsorbed through functional groups containing oxygen on the Mn-Goe structure. The enhancement of Mn-substitution for the uranium(VI) sorption capacity of goethite was revealed. This study suggests that goethite and Mn-Goe can both play a significant role in controlling the mobility and transport of uranium(VI) in the subsurface environment, which is helpful for material development in environmental remediation.

The impact of nanoplastics (NP) using model polystyrene nanoparticles amine functionalized (PS–NH₂) has been investigated on pigment and lipid compositions of the marine diatom Chaetoceros neogracile, at two growth phases using a low (0.05 μg mL⁻¹) and a high (5 μg mL⁻¹) concentrations for 96 h. Results evidenced an impact on pigment composition associated to the light-harvesting function and photoprotection mainly at exponential phase. NP also impacted lipid composition of diatoms with a re-adjustment of lipid classes and fatty acids noteworthy. Main changes upon NP exposure were observed in galactolipids and triacylglycerol’s at both growth phases affecting the thylakoids membrane structure and cellular energy reserve of diatoms. Particularly, exponential cultures exposed to high NP concentration showed an impairment of long chain fatty acids synthesis. Changes in pigment and lipid content of diatom’ cells revealed that algae physiology is determinant in the way cells adjust their thylakoid membrane composition to cope with NP contamination stress. Compositions of reserve and membrane lipids are proposed as sensitive markers to assess the impact of NP exposure, including at potential predicted environmental doses, on marine organisms.