Uptake of 17β-estradiol and biomarker responses in brown trout (Salmo trutta) exposed to pulses

In streams, chemicals such as 17β-estradiol (E2) are likely to occur in pulses. We investigated uptake and biomarker responses in juvenile brown trout (Salmo trutta) of 3- or 6-h pulses of concentrations up to 370 ng E2 L⁻¹. Uptake by the fish was estimated from disappearance of E2 from tank water. A single 6-h pulse of 370 ng E2 L⁻¹ increased the plasma vitellogenin concentration, liver Erα- and vitellogenin-mRNA. Exposure to 150-160 ng E2 L⁻¹ for 6 h increased vitellogenin in one experiment but not in another. Two 6-h pulses had a larger effect one pulse. Brown trout in the size range 24-74 g took up E2 linearly with time and exposure concentration with a concentration ratio rate of 20.2 h⁻¹. In conclusion, the threshold for induction of estrogenic effects in juvenile brown trout at short term pulse exposure appears to be in the range 150-200 ng E2 L⁻¹.     

Assessing estrogenic activity in surface water and sediment of the Liao River system in northeast China using combined chemical and biological tools

This paper investigated some selected estrogenic compounds (4-t-octylphenol: 4-t-OP; 4-nonylphenols: 4-NP; bisphenol-A: BPA; diethylstilbestrol: DES; estrone: E1; 17β-estradiol: E2; 17α-Ethinylestradiol: EE2; triclosan: TCS) and estrogenicity in the Liao River system using the combined chemical and in vitro yeast screen bioassay and assessed their ecological risks to aquatic organisms. The estrogenic compounds 4-t-OP, 4-NP, BPA, E1, E2 and TCS were detected in most of the samples, with their concentrations up to 52.1 2065.7, 755.6, 55.8, 7.4 and 81.3 ng/L in water, and up to 8.6, 558.4, 33.8, 7.9, <LOQ and 33.9 ng/g in sediment, respectively. However, DES and EE2 were not detected in the Liao River. The estrogen equivalents (EEQ) of the water and sediment samples were also measured by the bioassay. High estrogenic risks to aquatic organisms were found in the river sections of metropolitan areas and the lower reach of the river system.     

Air-water PCB fluxes from southwestern Lake Michigan revisited

From simultaneous air and water polychlorinated biphenyl (PCB) measurements collected in September 2010, we re-evaluated the direction and magnitude of net air-water exchange of PCBs in southwest Lake Michigan and compared them with estimations made using similar approaches 15 years prior. Air and water samples were collected during a research expedition on Lake Michigan at 5 km off the coast of Chicago, with prevailing winds from the southwest of our location. Gas-phase ΣPCB concentrations ranged from 190 to 1100 pg m^?3 with a median of 770 pg m^?3, which is similar to the concentrations measured in the City of Chicago at the same time and similar to concentrations measured in this part of the lake over the last 20 years. Water dissolved-phase ΣPCB concentrations ranged from 150 to 170 pg L^?1 with a median of 160 pg L^?1, which is one-tenth of that measured in the 1990s. ?PCB net fluxes showed a slightly absorptive behavior, with a median of (?) 21 ng m^?2 day^?1 and an interquartile range of (?) 47 to (+) 5 ng m^?2 day^?1, where (?) and (+) fluxes indicate absorption and volatilization, respectively. Airborne PCB concentrations were higher when the winds were coming from Chicago and drive the deposition. Our fluxes are not significantly different from estimations from 1994 and 1995 and suggest that absorption of PCBs into the waters is slightly more prevalent than 15 years ago. It was confirmed that Chicago remains an important atmospheric source of PCBs to Lake Michigan.

     

Occurrence,distribution, and risk assessment of antibiotics in the Songhua River in China

The occurrence, distribution, and risk assessment of antibiotics in freshwater systems are receiving global attention, because of their impact on the environment and human health. However, few studies have focused on this topic in Northeast China and its Songhua River, the third-largest river in China. This study investigated the occurrence and distribution of 12 antibiotics, including three cephalosporins (cefazolin, cefmetazole, cefotaxime), three macrolides (azithromycin, clarithromycin, roxithromycin), three fluoroquinolones (ofloxacin, norfloxacin, flumequine), and three sulfonamides (sulfadiazine, sulfapyridine, sulfamethoxazole) in the mainstream and tributaries of the Songhua River. A total of 152 surface water samples were collected in January, May, July, and October 2016. These samples were analyzed using solid-phase extraction (SPE) and ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The results indicated the wide use of all 12 antibiotics in the mainstream of the Songhua River. Sulfamethoxazole and cefazolin were the dominant antibiotics, with maximum concentrations of 73.1 and 65.4 ng L^?1, respectively. Other antibiotics were present at mean concentrations below 15 ng L^?1, except cefmetazole, present at a mean concentration of 35.6 ng L^?1. The spatial distribution of antibiotics showed that unbalanced regional development may lead to the distribution pattern of the antibiotics in the tributaries and the mainstream. Thus study also assessed the seasonal variation of antibiotics in urban surface water; cephalosporin, sulfonamide, fluoroquinolone, and macrolide concentrations were significantly higher during the icebound season than during non-icebound season. This may be due to the low temperature and water flow of the river in winter. Risk assessment showed that azithromycin, clarithromycin, roxithromycin, flumequine, and sulfamethoxazole posed a low or median risk to the aquatic organisms in the mainstream. The potential risks created by antibiotics to the aquatic environment should not be neglected in the Songhua River. The potential risks created by antibiotics to the aquatic environment should not be neglected in the Songhua River.

     

Characteristics of atmospheric speciated mercury concentrations (TGM,Hg(II) and Hg(p)) in Seoul,Korea

Ambient speciated mercury concentrations including total gaseous mercury (TGM), gaseous divalent mercury (Hg(II)), and particulate mercury (Hg(p)) were measured on the roof of the Graduate School of Public Health building in Seoul, Korea from February 2005 to February 2006. The average concentrations were 3.22 ± 2.10 ng m^?3, 27.2 ± 19.3 pg m^?3, and 23.9 ± 19.6 pg m^?3 for TGM, Hg(II), and Hg(p), respectively. Hg(II) and Hg(p) concentrations were higher during the daytime than during the nighttime, probably because of high photochemical activity. Hg⁰ concentrations were not significantly correlated with ozone however a positive correlation between ozone and Hg(II) was found during periods of high humidity. Eighteen days were characterized as pollution events with 24 h average PM_2.5 concentrations >65 μg m^?3. The average concentrations of TGM and Hg(p) during these events were 1.4–2 times higher than those during non-pollution events. In order to identify the contribution of long-range transported mercury to the enhanced mercury concentrations in Korea, an episode was defined as a period with hourly average TGM and CO concentrations higher than the monthly average TGM and CO concentrations and with significant enhancement of both TGM and CO concentrations for at least 10 h. A total of 70 episodes were identified during the sampling period: 36 local episodes and 34 long-range transport episodes. The mean ΔTGM/ΔCO slope for all episodes was 0.0063 ng m^?3 ppbv^?1 which agreed well with the slope (0.0036–0.0074 ng m^?3 ppbv^?1) found in previous studies that identified long-range transport of TGM from China. The mean slope during non-events was 0.0011 ng m^?3 ppbv^?1. Back-trajectory analysis showed that during episodes, air parcels arrived mostly from the major industrial areas in China (n = 25, 73%), followed by Japan (n = 4, 12%), Yellow Sea (n = 3, 9%), and Russia (n = 2, 6%).     

The distribution of 4-nonylphenol in marine organisms of North American Pacific Coast estuaries

One of the chemical breakdown products of nonylphenol ethoxylates, 4-nonylphenol (4-NP), accumulates in organisms and is of concern as an environmental pollutant due to its endocrine disrupting effects. We measured 4-NP levels in the seawater, sediment, and twelve organisms within the California estuary, Morro Bay, and examined biomagnification of 4-NP using stable isotope abundances (δ¹⁵N and δ¹³C) to quantify trophic position. 4-NP concentrations in organisms from Morro Bay included 25000 ± 8600 ng g⁻¹ lw in liver of California sea lion, 14000 ± 5600 ng g⁻¹ lw in liver of harbor porpoise, 138000 ± 55000 ng g⁻¹ lw in liver of sea otters, 15700 ± 3600 ng g⁻¹ lw in liver of seabirds, 36100 ± 6100 ng g⁻¹ lw in arrow goby fish, 62800 ± 28400 ng g⁻¹ lw in oysters, and 12700 ± 1300 ng g⁻¹ lw in mussels. 4-NP levels generally showed a pattern of trophic dilution among organisms in Morro Bay, with exceptions of biomagnification observed between three trophic links: mussel to sea otter (BMF 10.9), oyster to sea otter (BMF 2.2), and arrow goby to staghorn sculpin (BMF 2.7). Our examination of other west coast estuaries of USA and Canada revealed that mean 4-NP concentrations in gobies and mussels from Morro Bay were significantly higher than those from a more urbanized estuary, San Francisco Bay (goby: 11100 ± 3800 ng g⁻¹ lw) and from a remote estuary, Bamfield Inlet, Canada (goby: 9000 ± 900 ng g⁻¹ lw, mussel: 6100 ± 700 ng g⁻¹ lw). Relative to other estuaries worldwide, 4-NP levels in seawater (0.42 ± 0.16 μg L⁻¹) and sediment (53 ± 14 ng g⁻¹ dw) of Morro Bay are low, but gobies and oysters have higher 4-NP levels than comparable fauna.     

Ecotoxicological effects of typical personal care products on seed germination and seedling development of wheat (Triticum aestivum L.)

Biochemical responses of wheat (Triticum aestivum L.) seedlings stressed by two typical personal care products (PCPs) – triclosan (TCS) and galaxolide (HHCB) were experimentally investigated to assess their ecological risks. The results showed that wheat shoot and root elongation was significantly inhibited by 50–250 mg L⁻¹ TCS and HHCB. Wheat roots were sensitive to TCS, while shoots were sensitive to HHCB. The median effect concentration (EC₅₀) of TCS and HHCB based on the inhibition of their sensitive sites were 147.8 and 143.4 mg L⁻¹, respectively. Moreover, the damage of wheat seedlings treated by low concentration of TCS and HHCB during a long period cannot be neglected. After a 21-d exposure, 0.2–3.0 mg L⁻¹ TCS and HHCB treatment caused the damage to the accumulation of chlorophyll (CHL), the synthesis of soluble protein (SP), and the activity of peroxidase (POD) and superoxide dismutases (SOD) in different degree. However, different changing trends of these physiological indexes treated by different PCPs were observed after 7-d to 14-d exposures, especially the activity of POD and SOD. The activity of POD and SOD in wheat leaves and roots decreased with an increase in the concentration of TCS and the exposure time. However, the enzyme activities in wheat leaves treated by 0.2–3.0 mg L⁻¹ HHCB increased after a 14-d exposure, and with the prolongation of exposure time, the enzyme activities significantly decreased. The variations in these physiological indexes of wheat could be considered as good biomarkers of serious stress by TCS and HHCB in the environment.     

Endocrine disrupting activities in sewage effluent and river water determined by chemical analysis and in vitro assay in the context of granular activated carbon upgrade

As part of endocrine disruption in catchments (EDCAT) programme, this work aims to assess the temporal and spatial variations of endocrine disrupting chemicals (EDCs) in River Ray, before and after the commissioning of a full-scale granular activated carbon (GAC) plant at a sewage treatment works (STW). Through spot and passive sampling from effluent and river sites, estrogenic and anti-androgenic activities were determined by chemical analysis and in vitro bio-assay. A correlation was found between chemical analyses of the most potent estrogens (estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (EE2)) and yeast estrogen screen (YES) measurement, both showing clearly a reduction in estrogenic activity after the commissioning of the GAC plant at the STW. During the study period, the annual average concentrations of E1, E2 and EE2 had decreased from 3.5 ng L⁻¹, 3.1 ng L⁻¹ and 0.5 ng L⁻¹ to below their limit of detection (LOD), respectively, with a concentration reduction of at least 91%, 81% and 60%. Annual mean estrogenic activity measured by YES of spot samples varied from 1.9 ng L⁻¹ to 0.4 ng L⁻¹ E2 equivalent between 2006 and 2008 representing a 79% reduction. Similarly, anti-androgenic activity measured by yeast anti-androgen screen (anti-YAS) of spot samples was reduced from 148.8 to 22.4 μg flutamide L⁻¹, or by 85%. YES and anti-YAS values were related to each other, suggesting co-existence of both types of activities from chemical mixtures in environmental samples. The findings confirm the effectiveness of a full-scale GAC in removing both estrogenic and anti-androgenic activities from sewage effluent.     

Evaluation of the presence of drugs of abuse in tap waters

A total of seventy samples of drinking water were tested for non-controlled and illicit drugs. Of these, 43 were from Spanish cities, 15 from seven other European countries, three from Japan and nine from seven different Latin American countries. The most frequently detected compounds were caffeine, nicotine, cotinine, cocaine and its metabolite benzoylecgonine, methadone and its metabolite EDDP. The mean concentrations of non-controlled drugs were: for caffeine 50 and 19 ng L⁻¹, in Spanish and worldwide drinking water respectively and for nicotine 13 and 19 ng L⁻¹. Illicit drugs were sparsely present and usually at ultratrace level (<1 ng L⁻¹). For example, cocaine has mean values of 0.4 (Spain) and 0.3 ng L⁻¹ (worldwide), whereas for benzoylecgonine, these mean values were 0.4 and 1.8 ng L⁻¹, respectively. Higher concentrations of benzoylecgonine were found in Latin American samples (up to 15 ng L⁻¹). No opiates were identified in any sample but the presence of methadone and EDDP was frequently detected. Total mean values for EDDP were 0.4 ng L⁻¹ (Spain) and 0.3 ng L⁻¹ (worldwide). Very few samples tested positive for amphetamines, in line with the reactivity of chlorine with these compounds. No cannabinoids, LSD, ketamine, fentanyl and PCP were detected.     

Distribution of bisphenol-A, triclosan and n-nonylphenol in human adipose tissue, liver and brain

In this study, an analytical method was optimized for the determination of bisphenol-A (BPA), triclosan (TCS) and 4-n-nonylphenol (4n-NP), environmental contaminants with potential endocrine disruptive activities, in human tissues. The method consisted of a liquid extraction step, derivatization with pentafluorobenzoylchloride followed by a clean-up on acidified silica and detection with gas chromatography coupled with mass spectrometry (GC-ECNI/MS). Recoveries ranged between 92% and 102% with a precision below 5%. Limits of quantification ranged between 0.3-0.4 ng g⁻¹, 0.045-0.06 ng g⁻¹ and 0.003-0.004 ng g⁻¹ for BPA, TCS and 4n-NP in different tissues, respectively. The method was applied for the determination of BPA, TCS and 4n-NP in paired adipose tissue, liver and brain samples from 11 individuals. BPA could be detected in almost all tissues, with the highest concentrations found in adipose tissue (mean 3.78 ng g⁻¹), followed by liver (1.48 ng g⁻¹) and brain (0.91 ng g⁻¹). TCS showed the highest concentrations in liver (3.14 ng g⁻¹), followed by adipose tissue (0.61 ng g⁻¹), while it could be detected in only one brain sample. Levels of 4n-NP were much lower, mostly undetected, and therefore 4n-NP is considered of minor importance for human exposure. Despite the measurable concentrations in adipose tissue, these compounds seem to have a low bioaccumulation potential. The reported concentrations of free BPA in the various tissues are slight disagreement with pharmacokinetic models in humans and rats and therefore the possibility of external contamination with BPA during sample collection/storage cannot be ruled out.     

Evidence for short-range transport of atmospheric mercury to a rural,inland site

Atmospheric mercury (Hg) species, including gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and particulate-bound mercury (Hg_p), were monitored near three sites, including a cement plant (monitored in 2007 and 2008), an urban site and a rural site (both monitored in 2005 and 2008). Although the cement plant was a significant source of Hg emissions (for 2008, GEM: 2.20 ± 1.39 ng m^?3, RGM: 25.2 ± 52.8 pg m^?3, Hg_p 80.8 ± 283 pg m^?3), average GEM levels and daytime average dry depositional RGM flux were highest at the rural site, when all three sites were monitored sequentially in 2008 (rural site, GEM: 2.37 ± 1.26 ng m^?3, daytime RGM flux: 29 ± 40 ng m^?2 day^?1). Photochemical conversion of GEM was not the primary RGM source, as highest net RGM gains (75.9 pg m^?3, 99.0 pg m^?3, 149 m^?3) occurred within 3.0–5.3 h, while the theoretical time required was 14–23 h. Instead, simultaneous peaks in RGM, Hg_p, ozone (O₃), nitrogen oxides, and sulfur dioxide in the late afternoon suggested short-range transport of RGM from the urban center to the rural site. The rural site was located more inland, where the average water vapor mixing ratio was lower compared to the other two sites (in 2008, rural: 5.6 ± 1.4 g kg^?1, urban: 9.0 ± 1.1 g kg^?1, cement plant: 8.3 ± 2.2 g kg^?1). Together, these findings suggested short-range transport of O₃ from an urban area contributed to higher RGM deposition at the rural site, while drier conditions helped sustain elevated RGM levels. Results suggested less urbanized environments may be equally or perhaps more impacted by industrial atmospheric Hg emissions, compared to the urban areas from where Hg emissions originated.     

PM2.5 and PM10: The influence of sugarcane burning on potential cancer risk

In Brazil, sugarcane fields are often burned to facilitate manual harvesting, and this burning causes environmental pollution from the large amounts of soot released into the atmosphere. This material contains numerous organic compounds such as PAHs. In this study, the concentrations of PAHs in two particulate-matter fractions (PM_2.5 and PM₁₀) in the city of Araraquara (SE Brazil, with around 200,000 inhabitants and surrounded by sugarcane plantations) were determined during the sugarcane harvest (HV) and non-harvest (NHV) seasons in 2008 and 2009. The sampling strategy included four campaigns, with 60 samples in the NHV season and 220 samples in the HV season. The PM_2.5 and PM₁₀ fractions were collected using a dichotomous sampler (10 L min^?1, 24 h) with Teflon? filters. The filter sets were extracted (ultrasonic bath with hexane/acetone (1:1 v/v)) and analyzed by HPLC/Fluorescence. The median concentration for total PAHs (PM_2.5 in 2009) was 0.99 ng m^?3 (NHV) and 3.3 ng m^?3 (HV). In the HV season, the total concentration of carcinogenic PAHs (benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene) was 5 times higher than in the NHV season. B(a)P median concentrations were 0.017 ng m^?3 and 0.12 ng m^?3 for the NHV and HV seasons, respectively. The potential cancer risk associated with exposure through inhalation of these compounds was estimated based on the benzo[a]pyrene toxic equivalence (BaP_eq), where the overall toxicity of a PAH mixture is defined by the concentration of each compound multiplied by its relative toxic equivalence factor (TEF). BaP_eq median (2008 and 2009 years) ranged between 0.65 and 1.0 ng m^?3 and 1.2–1.4 ng m^?3 for the NHV and HV seasons, respectively. Considering that the maximum permissible BaP_eq in ambient air is 1 ng m^?3, related to the increased carcinogenic risk, our data suggest that the level of human exposure to PAHs in cities surrounded by sugarcane crops where the burning process is used is cause for concern.     

Effects of estrone on the early life stages and expression of vitellogenin and estrogen receptor genes of Japanese medaka (Oryzias latipes)

The fertilized eggs of Japanese medaka (Oryzias latipes) were exposed to estrone (E1) at 5–5000 ng L⁻¹ for 15 d, and the hatched fry were exposed continuously to the same concentrations for the additional 15 d. Adverse effects on hatchability, time to hatching, and gross abnormalities occurred at 50 ng L⁻¹ or above. Then the fry were divided into a continual exposure group, and a water recovery group. When the fry were exposed to E1 for another 60 d, there was a decrease in the hepatosomatic index (HSI) of males and the influence disappeared in the water recovery group. The gonadosonatic index (GSI) of females at 500 ng L⁻¹ decreased significantly in another 60 d exposure. While the fry were maintained in dechlorinated tap water for 60 d, a significant decrease in female GSI was observed at 50 ng L⁻¹ or above. An increased GSI was found in males in both continual exposure and water recovery groups at all E1 treatments. Quantitative RT-PCR showed that vitellogenin-I (Vtg-I) gene expressions in the female liver were significantly down-regulated at 50 ng L⁻¹ in the continual exposure group, and at 500 ng L⁻¹ in the water recovery group, while male Vtg-I genes were significantly up-regulated for all E1 treatments. In addition, all E1 treatments caused sex reversal of males. These results suggest that E1 at 5 ng L⁻¹ or above have unrecoverable impacts on the gonadal growth and development of medaka, even if only early life stages were exposed to E1.     

Intercomparison of the measurements of oxalic acid in aerosols by gas chromatography and ion chromatography

Oxalate, the anion of oxalic acid, is one of the most abundant measurable organic species in atmospheric aerosols. Traditionally, this bifunctional species has been measured by gas chromatography (GC) after derivatization to butyl ester and by ion chromatography (IC) without derivatization. However, there are few published comparisons of the two techniques. Here, we report the results of an intercomparison study for the measurement of oxalic acid in Arctic aerosols (<2.5 μm, n = 82) collected in 1992 using GC and IC. The concentrations of oxalic acid by GC ranged from 6.5–59.1 ng m^?3 (av. 26.0 ng m^?3, median 26.2 ng m^?3) whereas those by IC ranged from 6.6–52.1 ng m^?3 (av. 26.6 ng m^?3, median 25.4 ng m^?3). They showed a good correlation (r = 0.84) with a slope of 0.96. Thus, observations of oxalate obtained by GC employing dibutyl esters are almost equal to those by IC. Because the accuracy of oxalic acid by GC method largely depends on the method used, it is important to strictly examine the recovery in each study.     

Seasonal variability in gaseous mercury fluxes measured in a high-elevation meadow

Seasonal patterns of atmospheric mercury (Hg) fluxes measured over vegetated terrestrial systems can provide insight into the underlying process controlling emission and deposition of Hg to vegetated surfaces. Gaseous elemental Hg fluxes were measured for week-long periods in each season (spring, summer, fall, and winter) over an uncontaminated high-elevation wetland meadow in Shenandoah National Park, Virginia using micrometeorological methods. Mean net deposition was observed in the spring (?4.8 ng m^?2 h^?1), emission in the summer (2.5 ng m^?2 h^?1), near zero flux in the fall (0.3 ng m^?2 h^?1), and emission in the winter (4.1 ng m^?2 h^?1). Nighttime deposition (when stomata are closed) and the poor correlation between Hg fluxes and canopy conductance during periods of active vegetation growth suggest that stomatal processes are not the dominant mechanism for ecosystem-level GEM exchange at this site. The strong springtime deposition relative to summer implies that young vegetation is better at scavenging Hg, with the highest deposition occurring at night possibly via a cuticular pathway. These results suggest that spring is a period of GEM deposition while other seasons exhibit net emission, emphasizing the importance of capturing GEM flux seasonality when determining total Hg budgets.     

Organochlorine pesticides in surface sediments and suspended particulate matters from the Yangtze estuary, China

Total HCHs' and total DDTs' levels in surface sediments (SS) ranged from 0.5 to 17.5 ng g⁻¹ and from 0.9 to 33.1 ng g⁻¹, averaged 6.0 and 8.2 ng g⁻¹, respectively. Total HCHs' and total DDTs' levels in suspended particulate matters (SPM) varied from 6.2 to 14.8 ng g⁻¹ with a mean value of 12.3 ng g⁻¹ and were from 3.4 to 25.7 ng g⁻¹ with an average of 16.4 ng g⁻¹, respectively. Lindane is the main HCHs' source and continuing use in the Yangtze Delta areas of ‘pure’ γ-HCH (lindane) rather than technical HCH (a mix of largely α- and some γ-HCH). DDTs in SS are mainly accumulated in history. However, high DDT fractions in SPM are indicators of new input of typical dicofol type DDT from 2002 to 2004. It can be seen that most samples from the Yangtze estuary were in ranges where adverse biological effects are expected, either occasionally or frequently.     

NOX fluxes from several typical agricultural fields during summer-autumn in the Yangtze Delta,China

NO_X fluxes from three kinds of vegetable lands and a rice field were measured during summer–autumn in the Yangtze Delta, China. The average NO fluxes from the rice fields (RF), celery field (CE), maize field (MA) and cowpea field (CP) were 4.1, 30.8, 54 and 32.2 ng N m^?2 s^?1, respectively; and the average NO₂ fluxes were ?2.12, 0.68, 1.33 and 0.5 ng N m^?2 s^?1, respectively. The liquid N fertilizer (the mixture of swine excrement and urine) which is widely applied to vegetable lands by Chinese farmers was found to quickly stimulate NO emission, and have significant contribution to NO emission from the investigated vegetable lands. Apparent linearity correlations were found between NO₂ fluxes and the ambient concentrations of the rice fields, with a compensation point of about 2.84 μg m^?3. Total emissions of NO during summer–autumn time from this area were roughly estimated to be 4.1 and 8.4 Gg N for rice field and vegetable lands, respectively.     

Water-soluble organic compounds at a mountain-top site in Colorado,USA

Water extracts of atmospheric particulate matter (PM_2.5) collected at the Storm Peak Laboratory (SPL) (3210 MSL, 40.45° N, 106.74° W) were analyzed for a wide variety of polar organic compounds. The unique geographical character of SPL allows for extended observations/sampling of the free tropospheric interface. Under variable meteorological conditions between January 9th and January14th 2007, the most abundant compounds were levoglucosan (9–72 ng m^?3), palmitic acid (10–40 ng m^?3) and succinic acid (18–27 ng m^?3). Of 84 analytes included in the GC–MS method, over 50 individual water extractable polar organic compounds (POC) were present at concentrations greater than 0.1 ng m^?3. During a snow event (Jan. 11th–13th), the concentrations of several presumed atmospheric transformation compounds (dicarboxylic acids) were reduced. Lower actinic flux, reduced transport distance, and ice crystal scavenging may explain this variability. Diurnal averages over the sampling period revealed a higher total concentration of water extractable POC at night, 211 ng m^?3 (105–265 ng m^?3), versus day, 160 ng m^?3 (137–205 ng m^?3), which suggests a more aged nighttime aerosol character. This may be due to the increased daytime convective mixing of local primary emissions from the Yampa Valley. XAD resin extracts revealed a gas-phase partitioning of several compounds, and analysis of cloud water collected at this site in 2002 revealed a similar compound abundance trend. Levoglucosan, a wood smoke tracer was generally found to be the most abundant compound in both aerosol and cloud water samples. Variations in meteorological parameters and local/regional transport analysis play an important interpretive role in understanding these results.     

Atmospheric phosphorus deposition at a montane site: Size distribution,effects of wildfire,and ecological implications

The dry deposition of atmospheric particulate matter can be a significant source of phosphorus (P) to oligotrophic aquatic ecosystems, including high-elevation lakes. In this study, measurements of the mass concentration and size distribution of aerosol particles and associated particulate P are reported for the southern Sierra Nevada, California, for the period July–October, 2008. Coarse and fine particle samples were collected with Stacked Filter Units and analyzed for Total P (TP) and inorganic P (IP) using a digestion-extraction procedure, with organic P (OP) calculated by difference. Particle size-resolved mass and TP distributions were determined concurrently using a MOUDI cascade impactor. Aerosol mass concentrations were significantly elevated at the study site, primarily due to transport from offsite and emissions from local and regional wildfires. Atmospheric TP concentrations ranged from 11 to 75 ng m^?3 (mean = 37 ± 16 ng m^?3), and were typically dominated by IP. Phosphorus was concentrated in the coarse (>1 μm diameter) particle fraction and was particularly enriched in the 1.0–3.2 μm size range, which accounted for 30–60% of the atmospheric TP load. Wildfire emissions varied widely in P content, and may be related to fire intensity. The estimated dry depositional flux of TP for each daily sampling period ranged between 7 and 118 μg m^?2 d^?1, with a mean value of 40 ± 27 μg m^?2 d^?1. Relative rates of dry deposition of N and P in the Sierra Nevada are consistent with increasing incidence of N limitation of phytoplankton growth and previously observed long-term eutrophication of lakes.     

Monitoring of organic pollutants in marine environment by semipermeable membrane devices and mussels: accumulation and biochemical responses

This study involves the monitoring of organic pollutants using transplanted mussels (Mytilus galloprovincialis) as bioindicator organisms and semipermeable membrane devices (SPMDs) as passive samplers. Mussels and SPMDs were deployed to marinas, shipyards and shipbreaking yards on the coastal area of Turkey and retrieved after 60 days. Polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and organochlorine pesticide (OCP) compounds were analysed with high-resolution GC-MS. Total PAH concentrations in SPMDs and mussels ranged from 200 to 4740 ng g sampler^?1 and from 7.0 to 1130 ng g^?1 in wet weight (ww). PCB and OCP concentrations in SPMDs changed between 0.04–200 and 4.0–26 ng g sampler^?1, respectively. The highest PCB (190 ng g^?1 ww) and OCP (200 ng g^?1 ww) concentrations in mussels were measured at shipyard stations. A strong correlation was observed between the PAH and PCB concentrations in SPMDs and mussels. Enzyme assays (acetylcholinesterase, ethoxyresorufin-O-deethylase, glutathione S-transferase, glutathion reductase and carboxylesterase activities) were performed as biomarkers to reveal the effects of pollution on the mussels. There was no clear relationship found between the enzyme levels and the pollutant concentrations in mussels. Integrated biomarker responses were calculated to interpret the overall effect of pollutants.