Plutonium in the environment has drawn significant attentions due to its radiotoxicity in high concentration and source term linked with nuclear accidents and contaminations. The isotopic ratio of plutonium is source dependent and can be used as a fingerprint to discriminate the sources of radioactive contaminant. ²³⁹Pu, ²⁴⁰Pu and ¹³⁷Cs in surface soil and soil cores collected from Northern Xinjiang were determined in this work. The concentrations of ²³⁹,²⁴⁰Pu and ¹³⁷Cs are in the range of 0.06–1.20 Bq kg⁻¹, and <1.0–31.4 Bq kg⁻¹ (decay corrected to Sep. 2017), respectively, falling in the ranges of global fallout in this latitude zone. The ²⁴⁰Pu/²³⁹Pu atomic ratios of 0.118–0.209 and ²³⁹,²⁴⁰Pu/¹³⁷Cs activity ratios of 0.039–0.215 were measured. Among the investigated sites, distinctly lower ²⁴⁰Pu/²³⁹Pu atomic ratios of 0.118–0.133 and higher ²³⁹,²⁴⁰Pu/¹³⁷Cs activity ratios of 0.065–0.215 compared to the global fallout values were observed in the northwest part, indicating a significant contribution from other source besides the global fallout. This extra source is mainly attributed to the releases of atmospheric nuclear weapons testing at Semipalatinsk Nuclear Test Site, which was transported by the west and northwest wind through the river valley among mountains in this region. This contribution is estimated to account for 28–43% of the global fallout in the northwest part of Northern Xinjiang. The contribution from the Chinese atmospheric nuclear weapons testing to this region is negligible due to the lack of appropriate wind direction to transport the radioactive releases to this region.

Studies have showed that some of the most common male reproductive disorders present in adult life might have a fetal origin. Perfluorooctane sulfonic (PFOS) is one of the major environmental pollutants that may affect the development of male reproductive system if exposed during fetal or pubertal periods. However, whether PFOS exposure during fetal period affects testicular functions in the adult is still unclear. Herein, we investigated the effects of a brief gestational exposure to PFOS on the development of adult Leydig- and Sertoli-cells in the male offspring. Eighteen pregnant Sprague-Dawley rats were randomly divided into three groups and each received 0, 1 or 5 mg/kg/day PFOS from gestational day 5–20. The testicular functions of F1 males were evaluated on day 1, 35 and 90 after birth. PFOS treatment significantly decreased serum testosterone levels of animals by all three ages examined. The expression level of multiple mRNAs and proteins of Leydig (Scarb1, Cyp11a1, Cyp17a1 and Hsd17b3) and Sertoli (Dhh and Sox9) cells were also down-regulated by day 1 and 90. PFOS exposure might also inhibit Leydig cell proliferation since the number of PCNA-positive Leydig cells were significantly reduced by postnatal day 35. Accompanied by changes in Leydig cell proliferation and differentiation, PFOS also significantly reduced phosphorylation of glycogen synthase kinase-3β while increased phosphorylation of β-catenin. In conclusion, gestational PFOS exposure may have significant long-term effects on adult testicular functions of the F1 offspring. Changes in Wnt signaling may play a role in the process.

Polybrominated biphenyl ethers (PBDEs) are commonly added to electronic products for flame-retardation effects, and are attracting more and more attentions due to their potential toxicity, durability and bioaccumulation. This study conducts a sysmtematic review to understand the human exposure to PBDEs from e-waste recycling, especially exploring the exposure pathways and human burden of PBDEs as well as investigating the temporal trend of PBDEs exposure worldwide. The results show that the particular foods (contaminated fish, poultry, meat and breast milk) ingestion, indoor dust ingestion and indoor air inhalation may be key factors leading to human health risks of PBDEs exposure in e-waste recycling regions. Residents and some vulnerable groups (occupational workers and children) in e-waste recycling areas may face higher exposure levels and health risks. PBDE exposure is closely related to exposure level, exposure duration, e-waste recycling methods, and dietary customs. High levels of PBDEs are found in human tissues (breast milk, hair, blood (serum), placenta and other tissues) in e-waste areas, at far higher levels than in other areas. Existing data indicate that PBDE exposure levels do not present any apparent downward trend, and will possibly cause serious human diseases. More epidemiological studies are still needed to provide a solid basis for health risk assessment.

This study reports a characterization of indoor polycyclic aromatic hydrocarbons (PAHs) associated with dust (dust-PAHs) in household evaporative coolers and their associated health effects. Extensive analysis showed that the indoor dust-PAHs stemmed mostly from pyrogenic sources (vehicular emissions) with mean total concentrations limited between 131 and 429 ng g−1. The distribution pattern of PAHs based on number of rings exhibited the following order of decreasing relative abundance: 4 > 3 > 5 > 6 > 2 rings. Results indicate that the mutagenicity of dust-PAHs exceeded their carcinogenicity, but that the potential carcinogenic effects are still significant. The mean lifetime cancer risk for different age groups for three pathways based on Model 2 (dermal (1.39 × 10−1 to 1.91 × 10−2), ingestion (2.13 × 10−3 to 8.08 × 10−3) and inhalation (1.62 × 10−7 to 4.06 × 10−7)) was 7.4–146 times higher than values predicted by Model 1 (dermal (5.13 × 10−5 to 3.03 × 10−3), ingestion (9.34 × 10−5 to 1.31 × 10−3) and inhalation (7.13 × 10−20 to 1.68 × 10−20)). Hence, exposure to dust-PAHs in household evaporative coolers lead to high risk, especially for children (less than 11 years) (HQ = 2.71 × 10−20 to 54.8 and LTCRs = 7.13 × 10−20 to 1.39 × 10−1). Strategies should be considered to eliminate such pollutants to protect people, especially children, from the non-carcinogenic and carcinogenic effects by changing household evaporative coolers with other cooling systems.

Two typical polycyclic musks (PCMs), namely 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), were determined in 63 surface water and 42 sediment samples collected from the North Canal River watershed, an urban catchment located in the megacity Beijing, China. Concentrations of HHCB and AHTN were 13.2 ng/L–395 ng/L and 2.98 ng/L–232 ng/L in surface water, while 4.10 ng/g–818 ng/g and 1.21 ng/g–731 ng/g in sediments. The results showed that PCM concentrations in the North Canal River watershed were at the high end when compared to that in other regions in China and worldwide. A watershed-wide annual mass budget showed that HHCB (∼150 kg/year) and AHTN (∼80 kg/year) mainly originated from urban wastewaters. Both PCMs were eliminated primarily by outflowing water (72 kg/year and 43 kg/year for HHCB and AHTN, respectively) and due to losses to the atmosphere (40 kg/year and 26 kg/year for HHCB and AHTN, respectively). An assessment of ecological risks posed by HHCB and AHTN to aquatic organisms in the North Canal River watershed was performed by using a tiered ecological risk assessment. The results showed that PCMs were unlikely to pose an ecological risk at the watershed scale (the probability of the incidence of adverse effect was <3.5% at the 99% protection level). However, according to the results from the risk quotient method, the tributaries draining wastewater effluents should be hotspots that warrant further research in future.

Due to population growth and increased production of municipal solid waste, it is important to utilize this unused energy source, With the right technology, this resource can be used as energy production. Sources of biomass include various natural and derived materials, such as woody and herbaceous species, solid wastes (e.g. from forest thinning and harvesting, timber production and carpentry residues), agricultural and industrial residues, waste paper, municipal solid waste, sawdust, grass, waste from food processing, animal wastes, aquatic plants and industrial and energy crops grown for biomass In this study, in order to produce gas with high calorific value of solid waste in Tehran, a wide variety of compounds, steam and air intake fixed bed reactor has been investigated to identify the best combination. This essay will focus on the production of biogas with high calorific value. In this research, different compositions of air and steam as a reactor input have been examined and fixed base gasifier behavior in different situations have been specified which demonstrate that, best amount of air-steam composition with the most heat valuation is 12.26 (lb/s) for air input and 9.989 (lb/s) for steam input.

Abstract: Emissions of volatile organic compounds (VOCs) are major causes of tropospheric ozone and aerosol pollutions. This research provided information on ozone formation potential (OFP) and toxicity potential (TP) resulting from VOCs emission from a Nigeria petroleum depot. In this work, speciated VOCs were provided on basis of updated emissions within and around the depot. The observed concentration of individual VOCs and maximum incremental reactivity (MIR) coefficient were applied to assess the OFP of individual VOC in the ambient atmosphere. Major aromatic VOCs species were considered at various locations. The total OFP in the atmosphere of the depot is 1522.42 μg O3/m3. Toluene specie was revealed to be major contributor to OFP with 71.47% while others species were in descending order of benzene (9.16%), m-xylene (8.41%), ethyl benzene (3.98%), p-xylene (3.51%) and o-xylene (3.46%). The TP levels of aerosols pollutions were also reported with respect to locations. The Slop tank area had the highest OFP and TP level. An assessment of TP level and OFP suggests that occupants of some location within the depot are exposed to unhealthy air conditions. The study established that OFP and TP have a relationship within the atmosphere of the depot with respect to location. It is recommended that aggressive controlled measures of VOCs sources should be adopted within the petroleum depot as a way of curtailing the impact of tropospheric ozone and aerosol pollutions.

Among chemical industries, petroleum depots have been identified as large emitters of Volatile Organic Compounds (VOCs).They affect air quality and constitute serious health and environmental problems on the ecosystem. Air samples were collected over activated charcoal, using a low volume air sampler. The sampler was placed at a human breathing height of 1.5 m for a sampling period of 8 hours at seven different sampling locations as follows; Workshop area, Slop Tanks area, Gate 1, Tank Farm area, Gate 2, Otiyelu Village and Marketerâs Block. Desorption process was performed on the adsorbed activated charcoal using a solvent extraction method. The extracted solutions were subjected to Flame Ionization Detection analysis in a Gas Chromatograph using a capillary column HP 5MS with length, inner diameter and particle size set at (30 m à 0.25 mm à 0.25 μm). The Gas Chromatograph was powered with ChemStation RevA09.01 software to determine the concentrations of each of the VOCs species present. The sampling collection and quantitative analysis described above is consistent with ANSI/ASTM D-1605-60 procedure. The identified VOCs species emitted were characterized by toluene (52.84%), benzene (37.61%), xylene (5.67%), and ethyl benzene (3.88%). The observed concentrations uncovered the air tolerance limits set by United States Environmental Protection Agency and the Agency for Toxic Substances and Diseases Registry.

Pollution of water by heavy metals is a major problem such as mercury, lead, cadmium, cobalt, etc. The presence of toxic metals in the environment has detrimental effects on human and animal health and disrupts the balance and order of the ecosystem. Therefore, it is necessary to study the ways to eliminate these pollutants. The aim of this study was to compare nickel metal uptake by biological uptake methods with the help of bacterium and brown algae Sargasom, Focus and Grasilaria red algae and nanotechnology method. Based on the previous interpretations, the processes of removal of nickel from industrial wastewater was compared. Research question is that which method is more effective for removal of heavy metals? Results show that biosorption, as an environmentally friendly method, has a brilliant performance and is a low-cost internal method for wastewater treatment. The biological treatment of effluents is carried out by bacteria, some fungi, algae and protozoa to examine the conversion of effluent into a harmless state. Also results show that Iron-based nanostructured particles are capable of decomposing highly stable contaminants such as perchlorate compounds, air nitrate, heavy metals (nickel and mercury) and radioactive materials such as uranium dioxide. Nanostructured particles are used for immediate treatment of sediments, water treatment and liquid waste.

Sediments serve as both source and sink of contaminants (e.g., Cu) and biologically important materials (e.g., metals, nutrients). Bioturbation by benthic organisms is ecologically relevant as bioturbation affects the physio-chemical characteristics of sediments, thus altering nutrient and contaminant distribution and bioavailability. We examined the effects of sediment-associated Cu on T. tubifex with conventional toxicity endpoints, such as mortality and growth, and less commonly used non-destructive endpoints, such as bioturbation and feeding. An experimental approach was developed to examine the applicability of simple methods to detect effects on bioturbation and feeding. Two experiments were conducted with 7-day exposures to uncontaminated or Cu-spiked natural sediment at six Cu concentrations to examine Cu bioaccumulation and effects. Endpoints included worm mortality, feeding rate and growth (experiment A) and worm bioturbation (particle diffusion and maximum penetration depth, experiment B). A microparticle tracer was placed on the sediment surface and vertical particle transport was followed over time. Adverse effects were detected for all endpoints (bioturbation, feeding rate, growth and survival): a slight positive effect at the lowest Cu concentrations followed by adverse effects at higher concentrations indicating hormesis. These simple, non-destructive endpoints, provided valuable information and demonstrated that sediment-associated contaminants, such as Cu, can influence bioturbation activity, which in turn may affect the distribution of sediment-bound or particulate pollutants, such as the plastic microparticles studied here. Thus, we suggest to use simple endpoints, such as bioturbation and feeding rate, in ecotoxicity testing since these endpoint account for the influence of interactions between pollutants and benthos and, thus, increase ecological relevance.