Polycyclic aromatic hydrocarbon contamination in an urban area assessed by Quercus ilex leaves and soil

We investigated the PAH contamination of Naples urban area, densely populated and with high traffic flow, by analyses of environmental matrices: soil and Quercus ilex leaves. Being some PAHs demonstrated to have hazardous effects on human health, the accumulation of carcinogenic and toxic PAHs (expressed as B(a)Peq) was evaluated in the leaves and soil. The main sources of the PAHs were discriminated by the diagnostic ratios in the two matrices. The urban area appeared heavily contaminated by PAHs, showing in soil and leaves total PAH concentrations also fivefold higher than those from the remote area. The soil mainly accumulated heavy PAHs, whereas leaves the lightest ones. Median values of carcinogenic PAH concentrations were higher in soil (440 ng g^?1 d.w.) and leaves (340 ng g^?1 d.w.) from the urban than the remote area (60 and 70 ng g^?1 d.w., respectively, for soil and leaves). Also, median B(a)Peq concentrations were higher both in soil and leaves from the urban (137 and 63 ng g^?1 d.w., respectively) than those from the remote area (19 and 49 ng g^?1 d.w., respectively). Different from the soils, the diagnostic ratios found for the leaves discerned PAH sources in the remote and urban areas, highlighting a great contribution of vehicular traffic emission as main PAH source in the urban area.     

Assessing contamination of smoked sprats (Sprattus sprattus) with polycyclic aromatic hydrocarbons (PAHs) and changes in its level during storage in various types of packaging

The analysis of material used in this study demonstrated that the amount of polycyclic aromatic hydrocarbons (PAHs) in smoked sprats varies from the level below the lowest detection limit in muscles up to 9.99 µg kg^?1 of benzo[a]pyrene (BaP) in fish skin. Such a high level of PAHs in skin was reported only in one of six batches of sprats, while mean BaP level was at 1.69 µg kg^?1. Regardless such a high BaP level in skin, its concentration in muscles did not exceed the maximum acceptable level. The study objective was to assess to what extent packaging materials adsorb PAH compounds from food. Changes in the PAH levels were monitored in fish during their storage in packages made of various materials. The storage time was from 0 to 168 hours. The obtained results varied considerably, therefore their scatter did not allow to confirm unequivocally the preliminary hypothesis about the reduction of PAHs due to their migration to packaging material. However, analysis of the packaging used in this study demonstrated a significant increase in the level of total 16 PAHs. When high-density polyethylene (HDPE) packaging was analysed, a six-fold increase in the total 16 PAHs was observed comparing to the blank sample.     

Identification and source apportionment of polycyclic aromatic hydrocarbons in ambient air particulate matter of Riyadh, Saudi Arabia

In an effort to assess the occurrence and sources of polycyclic aromatic hydrocarbons (PAHs) in the ambient air of Riyadh, Saudi Arabia, PM₁₀ samples were collected during December 2010. Diagnostic PAH concentration ratios were used as a tool to identify and characterize the PAH sources. The results reflect high PM₁₀ and PAH concentrations (particulate matter (PM)?=?270–1,270 μg/m³). The corresponding average PAH concentrations were in the range of 18?±?8 to 1,003?±?597 ng/m³ and the total concentrations (total PAHs (TPAHs) of 17 compounds) varied from 1,383 to 13,470 ng/m³ with an average of 5,871?±?2,830 ng/m³. The detection and quantification limits were 1–3 and 1–10 ng/ml, respectively, with a recovery range of 42–80 %. The ratio of the sum of the concentrations of the nine major non-alkylated compounds to the total (CPAHs/TPAHs) was 0.87?±?0.10, and other ratios were determined to apportion the PM sources. The PAHs found are characteristic for emissions from traffic with diesel being a predominant source.     

Occurrence and distribution of veterinary antibiotics and tetracycline resistance genes in farmland soils around swine feedlots in Fujian Province, China

Six antibiotics, tetracyclines (TCs), and quinolones (QNs) in farmland soils from four coastal cities in Fujian Province of China were investigated. Oxytetracycline was most frequently detected, followed by enrofloxacin, ciprofloxacin, chlorotetracycline, ofloxacin, and tetracycline, with maximum concentrations of 613.2, 637.3, 237.3, 2668.9, 205.7, and 189.8 μg kg^?1, respectively. Samples from Putian City contained the highest maximum concentration of ∑TCs (3,064.2 μg kg^?1), whereas those from Fuzhou City contained the highest maximum concentration of ∑QNs (897.8 μg kg^?1). It is noteworthy that the ∑TCs and ∑QNs in 46.4 and 28.6 % of samples exceeded the ecotoxic effect trigger value (100 μg kg^?1), respectively. The concentrations of these antibiotics and five tetracycline resistance genes in four soil plots at depth profiles were quantified thereafter. In most cases, both antibiotics and resistance genes decreased with the increase of depth. Some antibiotics can be detected at a depth of 60–80 cm where the abundance of tetO, tetM, and tetX reached up to 10⁷ copies g^?1. Additionally, the sum of all tet genes (normalized to 16S rRNA genes) correlated with ∑TCs significantly (r?=?0.676). Our results suggest that resistance determinants can migrate to deeper soil layers and would probably contaminate groundwater by vertical transport.     

Source,distribution, and health risk assessment of polycyclic aromatic hydrocarbons in urban street dust from Tianjin,China

To better assess and understand potential health risk of urban residents exposed to urban street dust, the total concentration, sources, and distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in 87 urban street dust samples from Tianjin as a Chinese megacity that has undergone rapid urbanization were investigated. In the meantime, potential sources of PAHs were identified using the principal component analysis (PCA), and the risk of residents’ exposure to PAHs via urban street dust was calculated using the Incremental Lifetime Cancer Risk (ILCR) model. The results showed that the total PAHs (∑PAHs) in urban street dust from Tianjin ranged from 538 μg kg^?1 to 34.3 mg kg^?1, averaging 7.99 mg kg^?1. According to PCA, the two to three- and four to six-ring PAHs contributed 10.3 and 89.7 % of ∑PAHs, respectively. The ratio of the sum of major combustion specific compounds (ΣCOMB)?/?∑PAHs varied from 0.57 to 0.79, averaging 0.64. The ratio of Ant/(Ant?+?Phe) varied from 0.05 to 0.41, averaging 0.10; Fla/(Fla?+?Pyr) from 0.40 to 0.68, averaging 0.60; BaA/(BaA?+?Chry) from 0.29 to 0.51, averaging 0.38; and IcdP/(IcdP?+?BghiP) from 0.07 to 0.37, averaging 0.22. The biomass combustion, coal combustion, and traffic emission were the main sources of PAHs in urban street dust with the similar proportion. According to the ILCR model, the total cancer risk for children and adults was up to 2.55?×?10^?5 and 9.33?×?10^?5, respectively.     

Risk assessment of PBDEs and PAHs in house dust in Kocaeli,Turkey: levels and sources

Indoor dust samples were collected from 40 homes in Kocaeli, Turkey and were analyzed simultaneously for 14 polybrominated diphenyl ethers (PBDEs) and 16 poly aromatic hydrocarbons (PAHs) isomers. The total concentrations of PBDEs (Σ₁₄PBDEs) ranged from 29.32 to 4790 ng g^?1, with a median of 316.1 ng g^?1, while the total indoor dust concentrations of 16 PAHs (Σ₁₆PAHs) extending over three to four orders of magnitude ranged from 85.91 to 40,359 ng g^?1 with a median value of 2489 ng g^?1. Although deca-PBDE products (BDE-209) were the principal source of PBDEs contamination in the homes (median, 138.3 ng g^?1), the correlation in the homes was indicative of similar sources for both the commercial penta and deca-PBDE formulas. The PAHs diagnostic ratios indicated that the main sources of PAHs measured in the indoor samples could be coal/biomass combustion, smoking, and cooking emissions. For children and adults, the contributions to ∑₁₄PBDEs exposure were approximately 93 and 25 % for the ingestion of indoor dust, and 7 and 75 % for dermal contact. Exposure to ∑₁₆PAHs through dermal contact was the dominant route for both children (90.6 %) and adults (99.7 %). For both groups, exposure by way of inhalation of indoor dust contaminated with PBDEs and PAHs was negligible. The hazard index (HI) values for BDE-47, BDE-99, BDE-153, and BDE-209 were lower than the safe limit of 1, and this result suggested that none of the population groups would be likely to experience potential health risk due to exposure to PBDEs from indoor dust in the study area. Considering only ingestion + dermal contact, the carcinogenic risk levels of both B2 PAHs and BDE-209 for adults were 6.2 × 10^?5 in the US EPA safe limit range while those for children were 5.6 × 10^?4 and slightly higher than the US EPA safe limit range (1 × 10^?6 and 1 × 10^?4). Certain precautions should be considered for children.     

Organochlorine pesticides and polychlorinated biphenyls in soils surrounding the Tanggu Chemical Industrial District of Tianjin, China

The spatial distribution of persistent organic pollutants (POPs) was examined in soils surrounding the Tanggu Chemical Industrial District in Tianjin, China. The concentrations of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzenes (HCBs), and polychlorinated biphenyls (PCBs) were determined in 70 surface soils using accelerated solvent extraction and gas chromatography with electron capture detection. The results showed that the ranges of ∑HCH, ∑DDT, ΣHCB, and ∑PCB concentrations in soils were 2.1–12,549 μg?kg^?1 (average, 965 μg?kg^?1), n.d.–2,033 μg?kg^?1 (average, 88.4 μg?kg^?1), n.d.–1,924 μg?kg^?1 (average, 349 μg?kg^?1), and n.d.–373 μg?kg^?1 (average, 46.2 μg?kg^?1), respectively. Of these, HCHs were the dominant POPs, accounting for 75 % of the total organochlorine pesticide (OCP) residues. Overall, the spatial distribution of OCP concentrations showed a decreasing trend from the center of the Tanggu District to the surrounding areas. Two major pollution sources were Tianjin Dagu Chemical Co., Ltd. in the district center and the Tianjin Chemical Plant in Hangu District. In contrast, PCB concentrations were relatively high in the Haihe estuary to the east and low to the west of the study area. Component analysis of OCPs in these soils showed that they mainly came from industrial point sources. Compared with soils in other regions, soil DDT pollution was at a medium level in the Tanggu Chemical Industrial District, but associated HCH, HCB, and PCB pollution was relatively heavy. By multivariate statistical analyses, Tianjin Dagu Chemical Co., Ltd. was recognized as the main source of POPs, and soil properties were clarified to play an important role on the distribution and composition of POPs, especially the organic carbon content.     

Accumulation pattern and distribution of polycyclic aromatic hydrocarbons (PAHs) in liver tissues of seven species of birds from Ahmedabad, India, during 2005–2007

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured in liver tissues of seven species of birds collected from Ahmedabad, India during 2005–2007. All the samples collected were dead as victims of kite flying. Concentrations of ∑PAHs in livers of birds were ranged from 110?±?32.6 ng/g wet wt (1,078?±?320 lipid wt) in common myna Acridotheres tristis to 382?±?90.1 ng/g (2,388?±?563 lipid wt) in white-backed vulture. Statistically significant (p?<?0.05) differences in ∑PAHs were observed among species. However, year of collection and sex of birds did not show significant differences in concentrations of PAHs. The levels of ∑PAHs measured in the present study species were higher than the levels documented for a number of avian species and were lower than those reported to have deleterious effects on survival or reproduction of birds. Presence of PAH residues in birds of Ahmedabad city show the continuous input of PAHs through environmental exposure. Although no threat is posed by any of the hydrocarbons detected, continuous monitoring of breeding colonies of birds is recommended in unpolluted reference sites as well as polluted sites. It is also the first account of a comprehensive analysis of PAHs in various species of birds in India. Therefore, the values reported in this study can serve as baseline values for future research.     

Heavy metal accumulation by poplar in calcareous soil with various degrees of multi-metal contamination: implications for phytoextraction and phytostabilization

The object of this study was to assess the capacity of Populus alba L. var. pyramidalis Bunge for phytoremediation of heavy metals on calcareous soils contaminated with multiple metals. In a pot culture experiment, a multi-metal-contaminated calcareous soil was mixed at different ratios with an uncontaminated, but otherwise similar soil, to establish a gradient of soil metal contamination levels. In a field experiment, poplars with different stand ages (3, 5, and 7 years) were sampled randomly in a wastewater-irrigated field. The concentrations of cadmium (Cd), Cu, lead (Pb), and zinc (Zn) in the poplar tissues and soil were determined. The accumulation of Cd and Zn was greatest in the leaves of P. pyramidalis, while Cu and Pb mainly accumulated in the roots. In the pot experiment, the highest tissue concentrations of Cd (40.76 mg kg^?1), Cu (8.21 mg kg^?1), Pb (41.62 mg kg^?1), and Zn (696 mg kg^?1) were all noted in the multi-metal-contaminated soil. Although extremely high levels of Cd and Zn accumulated in the leaves, phytoextraction using P. pyramidalis may take at least 24 and 16 years for Cd and Zn, respectively. The foliar concentrations of Cu and Pb were always within the normal ranges and were never higher than 8 and 5 mg kg^?1, respectively. The field experiment also revealed that the concentrations of all four metals in the bark were significantly higher than that in the wood. In addition, the tissue metal concentrations, together with the NH₄NO₃-extractable concentrations of metals in the root zone, decreased as the stand age increased. P. pyramidalis is suitable for phytostabilization of calcareous soils contaminated with multiple metals, but collection of the litter fall would be necessary due to the relatively high foliar concentrations of Cd and Zn.     

Characterization of PM2.5-bound polycyclic aromatic hydrocarbons in Atlanta—Seasonal variations at urban,suburban, and rural ambient air monitoring sites

Twenty-eight polycyclic aromatic hydrocarbons (PAH) and methylated PAHs (Me-PAH) were measured in daily PM_2.5 samples collected at an urban site, a suburban site, and a rural site in and near Atlanta during 2004 (5 samples/month/site). The suburban site, located near a major highway, had higher PM_2.5-bound PAH concentrations than did the urban site, and the rural site had the lowest PAH levels. Monthly variations are described for concentrations of total PAHs (∑PAHs) and individual PAHs. PAH concentrations were much higher in cold months than in warm months, with average monthly ∑PAH concentrations at the urban and suburban-highway monitoring sites ranging from 2.12 to 6.85 ng m^?3 during January–February and November–December 2004, compared to 0.38–0.98 ng m^?3 during May–September 2004. ∑PAH concentrations were found to be well correlated with PM_2.5 and organic carbon (OC) within seasons, and the fractions of PAHs in PM_2.5 and OC were higher in winter than in summer. Methyl phenanthrenes were present at higher levels than their un-substituted homologue (phenanthrene), suggesting a petrogenic (unburned petroleum products) input. Retene, a proposed tracer for biomass burning, peaked in March, the month with the highest acreage and frequency of prescribed burning and unplanned fires, and in December, during the high residential wood-burning season, indicating that retene might be a good marker for burning of all biomass materials. In contrast, potassium peaked only in December, indicating that it might be a more specific tracer for wood-burning.     

Responses of earthworm to aluminum toxicity in latosol

Excess aluminum (Al) in soils due to acid rain leaching is toxic to water resources and harmful to soil organisms and plants. This study investigated adverse impacts of Al levels upon earthworms (Eisenia fetida) from the latosol (acidic red soil). Laboratory experiments were performed to examine the survival and avoidance of earthworms from high Al concentrations and investigate the response of earthworms upon Al toxicity at seven different Al concentrations that ranged from 0 to 300 mg kg^?1 over a 28-day period. Our study showed that the rate of the earthworm survival was 100 % within the first 7 days and decreased as time elapsed, especially for the Al concentrations at 200 and 300 mg kg^?1. A very good linear correlation existed between the earthworm avoidance and the soil Al concentration. There was no Al toxicity to earthworms with the Al concentration ≤50 mg kg^?1, and the toxicity started with the Al concentration ≥100 mg kg^?1. Low Al concentration (i.e., <50 mg kg^?1) enhanced the growth of the earthworms, while high Al concentration (>100 mg kg^?1) retarded the growth of the earthworms. The weight of earthworms and the uptake of Al by earthworms increased with the Al concentrations from 0 to 50 mg kg^?1 and decreased with the Al concentrations from 50 to 300 mg kg^?1. The protein content in the earthworms decreased with the Al concentrations from 0 to 100 mg kg^?1 and increased from 100 to 300 mg kg^?1. In contrast, the catalase (CAT) and superoxide dismutase (SOD) activities in the earthworms increased with the Al concentrations from 0 to 100 mg kg^?1 and decreased from 100 to 300 mg kg^?1. The highest CAT and SOD activities and lowest protein content were found at the Al concentration of 100 mg kg^?1. Results suggest that a high level of Al content in latosol was harmful to earthworms.     

Polycyclic aromatic hydrocarbon emission from straw burning and the influence of combustion parameters

A simulated burning experiment was conducted in a tubular furnace system to examine the emission of polycyclic aromatic hydrocarbons (PAHs) from the burning of rice and bean straw, and the influence of combustion parameters was investigated. Total emission amounts of 16 PAHs (∑PAHs) from the burning of rice and bean straw ranged from 9.29 to 23.6 μg g^?1 and from 3.13 to 49.9 μg g^?1, respectively, which increased with the increase of temperatures from 200 to 700 °C. The contribution of combustion to individual PAH yields was about 80.6–100%, which was generally increased with the increase of burning temperature. Moisture content in straw had a negative effect on PAH formation, especially on PAHs with low molecular weight. ∑PAHs emission amounts decreased by 78.2% for bean straw with a moisture content of 30% in comparison with that for dried straw. In addition, PAH emission amounts increased with the increase of O₂ content in supplied air and then decreased, which showed a maximum emission at O₂ content of 40%. The source fingerprint of PAHs in emission from straw burning was established, which showed that naphthalene accounted for 35.0 ± 7.4% of ∑PAHs. Based on the experimental data, emission amounts of ∑PAHs from the burning of rice and bean straw were estimated to be 320–357 and 32.5–76.0 tons to ambient air per year in China, respectively.     

Development and validation of LC-MS/MS method for the determination of Ochratoxin A and its metabolite Ochratoxin α in poultry tissues and eggs

The objective of this study was to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the determination of Ochratoxin A (OTA) and Ochratoxin α (OTα) in poultry tissues and eggs. The two toxins were extracted by a mixture of acetonitrile/water, purified with a reversed phase C18 solid phase extraction column (SPE) and determined by LC-MS/MS. The LC-MS/MS method performances were evaluated in terms of linearity in solvent and in matrix (ranged from 0.5 to 15.10 µg L^?1 for OTA and from 0.60 to 17.85 µg L^?1 for OTα), limit of detection (LOD), limit of quantitation (LOQ), specificity, accuracy and precision in repeatability conditions. Recovery experiments were performed by spiking poultry liver, kidney, muscle and eggs around 1 µg kg^?1 and 10 µg kg^?1. LODs were 0.27 and 0.26 µg kg^?1 while LOQs were fixed at 1.0 and 1.2 µg kg^?1 for OTA and OTα, respectively. Main recoveries for OTA ranged from 82 to 109% and for OTα ranged from 55 to 89%. The values of within-laboratory relative standard deviation (RSD_r) were equal to or below 20%. Considering the results obtained and that all analytical performance criteria were fulfilled, the new extraction and purification method developed for OTA and OTα determination in animal tissues and eggs was found appropriate for control laboratories and research activities designed to ensure food safety.     

Temporal variation and spatial distribution of PAH in water of Three Gorges Reservoir during the complete impoundment period

Bioavailable concentrations of polycyclic aromatic hydrocarbons (PAHs) were investigated in water of Three Gorges Reservoir (TGR) using semipermeable membrane devices during the period of completely impounding water. ∑PAH concentrations in water of TGR in the period of completely impounding water were 15–381 ng?L^?1. ∑PAH concentrations increased from town or counties to big industrialized cities in TGR, indicating urbanization effects on PAH pollution in the water. Tributaries in TGR have a certain contribution of PAH pollution to the mainstream of Yangtze River and their pollution could not be neglected. An obvious decrease of PAH concentration was observed after 175-m water impounding in 2011 in TGR. Several factors may account for this decrease, including execution of comprehensive treatment and management measures in TGR, less rainfall in 2011, and sedimentation effect caused by the dam. Passive sampling method has been successfully applied in the investigation of trace PAH in water of TGR and proved to be a useful and efficient tool for the management and sustainable development of the big reservoir. The results of the study provide valuable information about PAH pollution in the whole reservoir including some tributaries, and the pollution status is dynamically related with human activities. Therefore, PAH could be used as a marker compound or indicator in the network monitoring system to surveil and trace the pollution status in TGR.     

Risk assessment of inhalation exposure to polycyclic aromatic hydrocarbons in school children

Polycyclic aromatic hydrocarbons (PAHs) associated with the inhalable fraction of particulate matter were determined for 1 year (2009–2010) at a school site located in proximity of industrial and heavy traffic roads in Delhi, India. PM₁₀ (aerodynamic diameter ≤10 μm) levels were ～11.6 times the World Health Organization standard. Vehicular (59.5 %) and coal combustion (40.5 %) sources accounted for the high levels of PAHs (range 38.1–217.3 ng m^?3) with four- and five-ring PAHs having ～80 % contribution. Total PAHs were dominated by carcinogenic species (～75 %) and B[a]P equivalent concentrations indicated highest exposure risks during winter. Extremely high daily inhalation exposure of PAHs was observed during winter (439.43 ng day^?1) followed by monsoon (232.59 ng day^?1) and summer (171.08 ng day^?1). Daily inhalation exposure of PAHs to school children during a day exhibited the trend school hours?>?commuting to school?>?resting period in all the seasons. Vehicular source contributions to daily PAH levels were significantly correlated (r?=?0.94, p?<?0.001) with the daily inhalation exposure level of school children. A conservative estimate of ～11 excess cancer cases in children during childhood due to inhalation exposure of PAHs has been made for Delhi.     

Characterization of contaminants and evaluation of the suitability for land application of maize and sludge biochars

Prior to the application of biochar as an agricultural improver, attention should be paid to the potential introduction of toxicants and resulting unintended impacts on the environment. In the present study, the concentrations of polycyclic aromatic hydrocarbons (PAHs), heavy metals, and mineral elements were determined in maize and sludge biochars produced at 100 °C increments between 200 and 700 °C. The concentration ranges of total PAHs were 358–5,136 μg kg^?1 in maize biochars and 179–70,385 μg kg^?1 in sludge biochars. The total heavy metals were detected at the following concentrations (mg kg^?1): Cu, 20.4–56.7; Zn, 59.7–133; Pb, 1.44–3.50; Cd, <0.014; Cr, 8.08–21.4; Ni, 4.38–9.82 in maize biochars and Cu, 149–202; Zn, 735–986; Pb, 54.7–74.2; Cd, 1.06–1.38; Cr, 180–247; Ni, 41.1–56.1 in sludge biochars. The total concentrations of PAHs and heavy metals in all maize biochars and most sludge biochars were below the control standards of sludge for agricultural use in China, the USA, and Europe. The leachable Mn concentrations in sludge biochars produced at below 500 °C exceeded the groundwater or drinking water standards of these countries. Overall, all the maize biochars were acceptable for land application, but sludge biochars generated at temperatures between 200 and 500 °C were unsuitable for application as soil amendments due to their potential adverse effects on soil and groundwater quality.     

Risk Assessment of 26 Polycyclic Aromatic Hydrocarbon (PAH) Compounds in Parkıng Garages

The aim of this study was to determine the level of 26 polycyclic aromatic hydrocarbons (PAHs) at parking garages and to provide the necessary annual information based on occupational inhalation exposure and non-occupational inhalation exposure, which carry risks for the environment. For this purpose, 22 samples were collected continuously from both gas and particulates phase PAHs from two parking garages at Konya City Center, Turkey. The exposure-based risk of these samples was evaluated using concentrations of the carcinogenic PAH compounds. None of the 26 PAHs measured had values exceeding the recommended exposure limits (RELs) standard values for inhalation rate recommended by the World Health Organization (WHO). Exposure levels of gas and particulate PAHs for the occupational group and the public (children and adults who spend time in shopping centers) were found to be 0.07–28.24 μgm^?3 and 0.05–5.753 μgm^?3, respectively, representing levels two to four times higher than those at the control site. Maximum daily inhalation of B[a]Py was estimated at 1.33 ngd^?1 for exposure of the public and as 274 ngd^?1 for the occupational group. It is believed that traffic makes a substantial contribution to the PAH profile, which had relatively high concentrations of naphthalene (Napth) and coronene (Coro). Highly carcinogenic dibenzo(a,l)pyrene (B[al]Pyre) was found in the ambient air at two parking garages. Napth and phenanthrene (Phen) were the main compounds found in nearly all the tested samples. In this study, benzo[e]pyrene (B[e]Py) was used as a reference for PAHs because its concentration is stable and does not change seasonally. Considering the importance of these compounds in relation to human health, the aim of this work was to characterize and quantify the more toxic PAHs in parking garages. Conducting PAH sampling and their chemical analysis is very costly and labor intensive. This study produced data that can be a powerful tool for environmental forensics.     

Determination of polycyclic aromatic hydrocarbons in dry tea

Twenty-eight different tea samples sold in the United States were evaluated using high-performance liquid chromatography (HPLC) with fluorescence detection (FLD) for their contamination with polycyclic aromatic hydrocarbons (PAHs). Many PAHs exhibit carcinogenic, mutagenic, and teratogenic properties and have been related to several kinds of cancer in man and experimental animals. The presence of PAHs in environmental samples such as water, sediments, and particulate air has been extensively studied, but food samples have received little attention. Eighteen PAHs congeners were analyzed, with percentage recovery higher than 85%. Contamination expressed as the sum of the 18 analyzed PAHs was between 101 and 1337 μg/kg on dry mass and the average contents in all of the 28 examined samples was 300 μg/kg on dry mass. Seven of the congeners were found in all samples with wide ranges of concentrations as follows: fluorene (7–48 μg/kg), anthracene (1–31 μg/kg), pyrene (1–970 μg/kg), benzo(a)anthracene (1–18 μg/kg) chrysene (17–365 μg/kg), benzo(a)pyrene (1–29 μg/kg), and indeno(1,2,3-cd)pyrene (4–119 μg/kg). The two most toxic congeners benzo(a)pyrene and dibenzo(a,h)anthracene were found at high concentrations only in Earl Grey Twinnings, Earl Grey Harney& Sons Fine Teas, and Chai Ultra Spice Black Tea Twinnings. Six PAH congeners are considered as suspected carcinogens (U.S.EPA), formed the basis of the estimation of the toxic equivalent (TEQ), Chai Ultra-Spice Black Tea Twinnings had the highest TEQ (110.9) followed by two grey tea samples, Earl Grey Harney & Sons Fine Tea (57.7) and Earl Grey Twinnings (54.5). Decaffeinated grey teas had the lowest TEQs, decaffeinated Earl Grey Bigelow (9.4) and Green Tea Honey Lemon Decaffeinated Lipton (9.6).     

Detection of antibiotics in chicken eggs obtained from supermarkets in Ho Chi Minh City,Vietnam

The residual levels of antibiotics in Vietnamese eggs were monitored from 2014 to 2015. A total of 111 egg packages, distributed by 11 different companies, were collected from supermarkets in Ho Chi Minh City and the levels of 28 antibiotics were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) screening method. Sixteen samples tested positive for antibiotics; a total of eight compounds (enrofloxacin, ciprofloxacin, norfloxacin, sulfadimethoxine, sulfamethazine, sulfamonomethoxine, tilmicosin and trimethoprim) were detected. Enrofloxacin was detected in eight samples, with two samples exhibiting concentrations exceeding 1,000 µg kg^?1. Tilmicosin was detected in three samples at a range of 49–568 µg kg^?1. We observed that two of the 11 companies frequently sold antibiotic-contaminated eggs (detection rates of 56 and 60%), suggesting that a number of companies do not regulate the use of antibiotics in egg-laying hens. Our findings indicate that livestock farmers require instruction regarding antibiotic use and that continual antibiotic monitoring is essential in Vietnam.     

Dissipation of spiromesifen and spiromesifen-enol on tomato fruit,tomato leaf,and soil under field and controlled environmental conditions

Dissipation of spiromesifen and its metabolite, spiromesifen-enol, on tomato fruit, tomato leaf, and soil was studied in the open field and controlled environmental conditions. Sample preparation was carried out by QuEChERS method and analysis using LC-MS/MS. Method validation for analysis of the compounds was carried out as per “single laboratory method validation guidelines.” Method validation studies gave satisfactory recoveries for spiromesifen and spiromesifen-enol (71.59–105.3%) with relative standard deviation (RSD) < 20%. LOD and LOQ of the method were 0.0015 μg mL^?1 and 0.005 mg kg^?1, respectively. Spiromesifen residues on tomato fruits were 0.855 and 1.545 mg kg^?1 in open field and 0.976 and 1.670 mg kg^?1 under polyhouse condition, from treatments at the standard and double doses of 125 and 250 g a.i. ha^?1, respectively. On tomato leaves, the residues were 5.64 and 8.226 mg kg^?1 in open field and 6.874 and 10.187 mg kg^?1 in the polyhouse. In soil, the residues were 0.532 and 1.032 mg kg^?1 and 0.486 and 0.925 mg kg^?1 under open field and polyhouse conditions, respectively. The half-life of degradation of spiromesifen on tomato fruit was 6–6.5 days in the open field and 8.1–9.3 days in the polyhouse. On tomato leaves, it was 7–7.6 and 17.6–18.4 days and in soil 5.6–7.4 and 8.4–9.5 days, respectively. Metabolite, spiromesifen-enol, was not detected in any of the sample throughout the study period. Photodegradation could be the major route for dissipation of spiromesifen in the tomato leaves, whereas in the fruits, it may be the combination of photodegradation and dilution due to fruit growth. The results of the study can be utilized for application of spiromesifen in plant protection of tomato crop under protected environmental conditions.