PCDDs/PCDFs in ambient air (<1 fg m−3) – The CTDEP long term sampling (30 d) method

The Connecticut Department of Environmental Protection (CTDEP) commenced monitoring for PCDDs/PCDFs (polychlorinated dibenzodioxins and polychlorinated dibenzofurans) in ambient air in 1987 and adopted the long term (30 d) sampling approach in 1993. The CTDEP method represents the first use of isotopically labeled PCDDs/PCDFs as field surrogates to monitor the behavior of native PCDDs/PCDFs present in actual ambient air samples. This feature first introduced in 1987 was later adopted by US EPA in revisions to sampling methods for PCDDs/PCDFs in ambient air (EPA Method TO9A) as well as development of EPA Reference Method 23 for measurement of PCDDs/PCFDs in stationary source emissions. Results are provided here for a total of twenty-three (23) samples (reported as pairs) representing twelve (12) 30 d sampling events conducted at a site located in metropolitan Hartford CT. Samples were collected in winter months during calendar years 2002–2008. PCDDs/PCDFs concentration data (pg m⁻³) are reported as both congener sums (Cl₄–Cl₈) and 2378-substitued congeners. Total PCDDs/PCDFs concentrations for these twelve (12) sampling events ranged from 0.68 pg m⁻³ (2003) to 4.18 pg m⁻³ (2004) with a mean concentration of 2.04 pg m⁻³.Method performance was monitored through use of collocated samples, in field isotopically labeled compounds, isotopically labeled laboratory applied internal standards and field blank samples. Method performance consistently exceeded goals established in USEPA Method TO9A for these same parameters. Average recoveries of in field labeled PCDDs/PCDFs ranged from 97.5% to 104.2%. Average (mean) recoveries for each of the ten (10) isotopically labeled internal standards ranged from 77.0% (¹³C-OCDF) to 95.5% (¹³C-2,3,7,8-TCDF). Method precision defined as % RPD data for collocated sampler pairs ranged from 8% to 14% for PCDDs and from 5% to 12% for PCDFs. The mean RPD for all PCDDs/PCDFs combined is 9.6%. Field monitoring results demonstrate method sensitivity for all PCDDs/PCDFs congeners and 2378-substituted congeners to be well below concentrations typically found for these compounds in ambient air (all reported data represent measured concentrations). Quantities (pg) found in field blanks represent the major determinant to achieving further enhancements in method sensitivity for selected congeners (OCDD < 42 fg m⁻³; 1,2,3,4,6,7,8-HpCDD < 5.7 fg m⁻³; and 1,2,3,4,6,7,8-HpCDF < 2.1 fg m⁻³). The CTDEP method represents a highly sensitive and reliable technique for monitoring of PCDDs/PCDFs congeners and other persistent organic pollutants (POPs) at ultra trace levels in ambient air (fg m⁻³).     

Levels and congener profiles of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls in cow’s milk collected in Campania, Italy

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and certain dioxin-like polychlorinated biphenyls (dl-PCBs) are a family of chemically-related lipophilic compounds characterized by similar toxicity. Due to their properties they are universally distributed in the environment and classified as persistent organic pollutants (POPs). From most of studies carried out to evaluate human dietary intake, milk and dairy products result as a major contributors of PCDD/Fs uptake. Of course the main source of milk contamination is animal feeds. Lactating ruminants, cows included, transfer these compounds to the food chain by ingestion of contaminated vegetables or soil. Their resistance to degradation and a high lipophilicity means that PCDD/Fs and dl-PCBs may be accumulated into fat tissues from which they are transferred to milk during lactation period.Seventy-nine cows milk samples, collected in the monitoring plan 2008, were analyzed for PCDD/Fs and dl-PCBs. Eleven milk samples were non-compliant corresponding to five breeding livestock located in Caserta province. The distribution of PCDD/Fs and dl-PCBs congeners in these samples was examined in order to determine the likely sources of dioxins. The results show that the congener profile is characterized by a prevalence of PCDFs in respect of PCDDs, that represents the typical pattern of thermal origin contamination.     

Levels of dioxins, furans and PCBs in human serum and milk of people living in Greece

In an attempt to evaluate the background levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho, mono-ortho and indicator polychlorinated biphenyls (PCBs) in people living in an urban (Athens) and a rural (Kozani) area of Greece, blood serum and mother milk samples were analyzed. Analytical results are reported in this study. Statistically significantly differences were observed between regions, sexes and ages. Contamination levels in blood and human milk from Greece reported here are low compared to the previously reported dioxin data from other European countries and give no indication of particular health risk.     

What are the sources and conditions responsible for exceedences of the 24 h PM10 limit value (50 μg m−3) at a heavily trafficked London site?

The European Union has set limit values for PM₁₀ to be met in 2005. At Marylebone Road, London, where the traffic is heavy, the daily limit value of 50 μg m⁻³ is exceeded more than 35 times a year. A total of 185 days with daily PM₁₀ concentrations exceeding the limit value of 50 μg m⁻³ measured between January 2002 and December 2004 (data capture of 89.5%) are discussed in this paper. These exceedences were more frequent in early spring and in autumn. Concentrations have been disaggregated into regional, urban (background) and local (street) contributions. Most of the episodes of gravimetric PM₁₀ above the limit value were associated with a high regional background and very often the regional contribution dominated the PM₁₀ mass. The secondary aerosol (especially the particulate nitrate) made a major contribution to the PM₁₀ load. These situations were frequently observed when air masses came from the European mainland (showing that both emissions from the UK and other EU countries contributed to the exceedences), and less frequently with maritime air masses that have stagnated over the UK (showing that emissions from the UK alone less frequently contributed to the high regional background). However, the higher frequency of episodes breaching the limit value at the roadside site than at the rural site and the higher frequency of PM₁₀ concentrations above the limit value on weekdays show that the high regional contributions are additional to local and urban emissions. Local emissions mainly due to traffic were the second important contributor to the exceedences, while the contribution of the urban background of London was less important than the local emissions and the regional background. Applying the pragmatic mass closure model of Harrison et al. [2003. A pragmatic mass closure model for airborne particulate matter at urban background and roadside sites. Atmospheric Environment 37, 4927–4933], revealed that the regional aerosol is comprised very largely of ammonium nitrate and sulphate and secondary organic aerosol. Findings suggest that international abatement of secondary aerosol precursors may be the most effective measure to fulfil the requirements of the European Directive 1999/30/CE by lowering the regional background.     

Levels of PCDDs, PCDFs and non-ortho PCBs in serum samples of non-exposed individuals living in Madrid (Spain)

In an attempt to evaluate the background levels of PCDDs, PCDFs and non-ortho PCBs in people living in Madrid (Spain), blood serum samples had been analyzed PCDD, PCDF and coplanar PCB levels from non exposed individuals are reported in this study. Average levels found were 515.29 ppt for total PCDDs, 66.73 ppt for total PCDFs and 85.47 ppt for non-ortho PCBs on a lipid weight basis Calculated I-TEQ values were 8.78 ppt for PCDDs, 6.96 for PCDFs and 7.03 for coplanar PCBs on a lipid weight basis.     

Levels of polychlorinated biphenyls and organochlorine pesticides in serum samples of Egyptian Vulture (Neophron percnopterus) from Spain

Concentrations of 23 polychlorinated biphenyls (PCBs), p,p'-DDT and two of its metabolites, p,p'-DDE and p,p'-TDE have been measured in serum samples of up to 1 ml of Egyptian Vulture (Neophron percnopterus) gathered from five populations in Spain. SigmaPCB concentrations were found to be in the range 3.2-97 ng/ml, while those of SigmaDDTs ranged from 0.93 to 38 ng/ml. p,p'-DDT/p,p'-DDE ratios higher than one were only found in the Segovia population, which could be an indication of recent use of p,p'-DDT in the area. In all cases, PCB profiles were dominated by congeners 52, 132 + 105, 138, 153 and 180. However, some differences among the five populations studied became evident when their profiles were compared with those of technical PCB mixtures by principal components analysis. The DDT and PCB levels detected in the serums analysed were lower than those previously reported for similar avian species and those reported to have deleterious effects on survival or reproduction of birds.     

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 3: alternatives to systemic insecticides

Environmental Science and Pollution Research - Over-reliance on pesticides for pest control is inflicting serious damage to the environmental services that underpin agricultural productivity. The...     

Levels of 3,3′,4,4′-tetrachloroazobenzene in herbicides and bulk reagents

The contamination levels of different commercial herbicides and bulk reagents with the carcinogen 3,3′,4,4′-tetrachloroazobenzene (TCAB) were determined by high resolution mass spectrometry. The concentrations vary from 0.00071 to 2.8 ug/g (ppm) for the herbicides and from 0.085 to 14 ug/g for the bulk reagents. They are thus lower than those of other reports.     

Acid rain and air pollution: 50 years of progress in environmental science and policy

Because of its serious large-scale effects on ecosystems and its transboundary nature, acid rain received for a few decades at the end of the last century wide scientific and public interest, leading to coordinated policy actions in Europe and North America. Through these actions, in particular those under the UNECE Convention on Long-range Transboundary Air Pollution, air emissions were substantially reduced, and ecosystem impacts decreased. Widespread scientific research, long-term monitoring, and integrated assessment modelling formed the basis for the policy agreements. In this paper, which is based on an international symposium organised to commemorate 50 years of successful integration of air pollution research and policy, we briefly describe the scientific findings that provided the foundation for the policy development. We also discuss important characteristics of the science–policy interactions, such as the critical loads concept and the large-scale ecosystem field studies. Finally, acid rain and air pollution are set in the context of future societal developments and needs, e.g. the UN’s Sustainable Development Goals. We also highlight the need to maintain and develop supporting scientific infrastructures.

     

Sources and concentration of nanoparticles (<10 nm diameter) in the urban atmosphere

Whilst limited information on particle size distributions and number concentrations in cities is available, very few data on the very smallest of particles, nanoparticles, have been recorded. Measurements in this study show that road traffic and stationary combustion sources generate a significant number of nanoparticles of diameter <10 nm. Measurements at the roadside (4 m from the kerb) and downwind from the traffic (more than 25 m from the kerb) show that nanoparticles (<10 nm diameter) accounted for more than 36–44% of the total particle number concentrations. Measurements designed to sample the plume of individual vehicles showed that both a diesel- and a petrol-fuelled vehicle generated nanoparticles (<10 nm diameter). The fraction of nanoparticles was even greater in a plume 350 m downwind of a stationary combustion source. On a few occasions, a temporal association between nanoparticles in the size range 3–7 nm and solar radiation was observed in urban background air at times when no other local sources were influential, which suggests that homogeneous nucleation can also be an important source of particles in the urban atmosphere.     

Prediction of maximum of 24-h average of PM10 concentrations 30 h in advance in Santiago,Chile

We have developed a neural network based model that uses values of PM10 concentrations measured until 6 p.m. on the present day plus measured and forecasted values of meteorological variables as input in order to predict the level reached by the maximum of the 24-h moving average (24MA) of PM10 concentration on the next day. We have adjusted the parameters of the model using 1998 data to predict 1999 conditions and 1999 data to forecast 2000 maximum concentrations. We have found that among the relevant meteorological input variables, the forecasted difference between maximum and minimum temperature is the most important. Due to the fact that local authorities impose restrictions to emissions on days when the maximum of 24MA of PM10 concentration is expected to exceed 240 μg/m³, we have corrected the measured concentrations on these days before evaluating the efficacy of the forecasting model. Percent errors in forecasting the numerical value are of the order of 20%. The performance of the neural network is better than that of a linear model with the same inputs, but the difference being not great is an indication that the right choice of input variables may be more important than the decision to use a linear or a nonlinear model.     

Solubilities of selected organic electronic materials in pressurized hot water and estimations of aqueous solubilities at 298.15 K

Increasing production and disposal of organic light-emitting diode (OLED) displays for smartphones and tablets may have impact on the environment depending on the aqueous solubility of the pertinent chemicals. Here, aqueous solubilities are presented for several compounds, mostly aromatic amines, used as hole transport materials in the OLED displays. Solute selection includes 1,4-bis(diphenylamino)benzene, tetra-N-phenylbenzidine, 4,4′-bis(N-carbazolyl)-1,1′-biphenyl, 1,3,5-tris(diphenylamino)benzene, and 9,10-bis(phenylethynyl)anthracene. The solubilities are those in pressurized hot water (PHW), i.e., measured at elevated temperature (up to 260 °C) and pressure. The semi-quantitative estimates of room-temperature solubilities of the solutes have been obtained from extrapolations of the solubilities in PHW. For the compounds studied, the estimated aqueous solubilities at room temperature do not exceed 2 × 10^?11 g of the solute per 1 kg of water. Aqueous solubilities of triphenylamine have also been measured and used to upgrade a recent group-contribution model of aqueous solubilities of organic nonelectrolytes with the parameters for the nitrogen atom in aromatic amines.     

The impact of an 8 h ozone air quality standard on ROG and NOx controls in Southern California

The new National Ambient Air Quality Standard for ozone in the US uses 8 h averaging for the concentration. Based on the 1993 ambient data for Southern California, 8 h averaging has a moderate tendency to move the location of the peak ozone concentration east of the location of the peak 1 h ozone concentration. Reducing the area-wide peak 8 h ozone concentration to 80 ppb would require an effective reduction of the area-wide peak 1 h ozone concentration to around 90 ppb. The Urban Airshed Model with improved numerical solvers, meteorological input based on a mesoscale model and an adjusted emissions inventory was used to study the effect of reactive organic gases (ROG) and NO_x controls on daily-maximum and peak 8 h ozone concentrations under the 26–28 August 1987 ozone episodic conditions in Southern California. The NO_x disbenefit remains prominent for the case of 8 h ozone concentration but is somewhat less prominent, especially when areal ozone exposure is considered, than the case for 1 h ozone concentration. The role of two indicators – O₃/NO_y and H₂O₂/HNO₃ – for NO_x- and ROG-sensitivity for 1 and 8 h ozone concentrations were also studied. In general, the indicator trends are consistent with model predictions, but the discriminating power of the indicators is rather limited.     

Hotspots analysis and perspectives of Prussian blue analogues (PBAs) in environment and energy in recent 20 years by CiteSpace

Environmental Science and Pollution Research - Prussian blue analogs (PBAs), a type of metal–organic frameworks (MOFs), have attracted much attention because of their large specific surface...     

The protective effect of green space on heat-related respiratory hospitalization among children under 5 years of age in Hanoi,Vietnam

Environmental Science and Pollution Research - Combined effects of global warming and rapid urbanization replace green spaces with urban facilities. Children in urban areas are at a higher risk of...     

Land-surface exchange in a chemically-reactive system; surface fluxes of HNO3, HCl and NH3

Vertical gradients from 0.25 to 2 m of NH₃, HNO₃ and HCl and associated aerosol components have been measured in the field above various surfaces in eastern England. The data have been examined to identify the effect, if any, of chemical reaction processes upon the observed vertical profiles. It is concluded that chemical transformations are too slow to influence concentration gradients and thus the surface exchange process. Assuming chemically conservative behaviour, deposition velocities for HNO₃ and HCl have been calculated; these lie within the range 0.4–7.7 cms⁻¹ and 0.4–6.9 cms⁻¹ for HNO₃ and HCl, respectively. Estimation of resistances to deposition indicates a negligible surface resistance for both species. Fluxes of ammonia were predominantly upward from the ground with a mean value of 0.031 μg m⁻²s⁻¹ which is consistent both with an emission inventory of the U.K. and with the measured atmospheric concentration of NH₃.     

Levels of synthetic musks; bromocyclene and PCBs in eel (Anguilla anguilla) and PCBs in sediment samples from some waters of Berlin/Germany.

The purpose of this study was to identify firstly the extent of contamination both of the aquatic biota and of sediments and secondly any regional differences in the concentrations of these compounds. In 1996, polychlorinated biphenyls (PCBs, including their coplanar congeners) were measured in 58 eel and 50 sediment samples. Furthermore, the veterinary pharmacetical bromocyclene and the nitro musks were determined in 84 (1995) and 122 (1996) eel samples. Polycyclic musk fragrances were additionally determined in analyses carried out in 1996. The mean values obtained during the two measurement periods (1995 and 1996) were 24 and 12 micrograms/kg fw. for musk xylene, 41 and 39 micrograms/kg fw. for musk ketone, 14 and 7 micrograms/kg fw. for bromocyclene and, in 1996, 592 micrograms/kg fw. for HHCB (maximum: 4131 micrograms/kg fw.). Decreasing contamination levels are seen for musk xylene and bromocylene but not for musk ketone. This tendency, and the high amounts of polycyclic musk fragrances in the edible parts of eel show that these musks are widely being used in place of nitro musks and that they reach the aquatic system via waste waters, especially those of sewage treatment plants. The mean levels of PCBs in the biota samples of a highly polluted area were 1227 micrograms/kg fw. or 119 pgTEQ/g (sediment: 203 micrograms/kg dw.) and of a slightly polluted area 340 micrograms/kg fw. or 49 TEQ/g (sediment: 47 micrograms/kg dw.).     

Degradation of 2,4-D in soils by Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticles combined with stimulating indigenous microbes

Purpose  

Degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in soils by Fe₃O₄ nanoparticles combined with soil indigenous microbes was investigated, and the effects of Fe₃O₄ nanoparticles on soil microbial populations and enzyme activities were also studied.     

Levels of DDT and PCB's in different stages of life cycle of the Arctic tern Sterna paradisaea and the herring gull Larus argentatus

∑DDT and PCB levels were analysed in samples of arctic terns and herring gulls collected in the archipelago of southwestern Finland. Special attention was paid to the levels at various stages of the life cycle and in different sexes. The levels were nearly ten times higher in the herring gull. The highest loads were found in adult birds and in newly hatched chicks but the levels were much lower (only 7–12 % in the herring gull) in chicks just before fledgling. The levels in young gulls remained low until the end of August at least. Therefore it is plausible that the high levels found in adult gulls are a consequence of their wintering in the southern Baltic.The levels of ∑DDT and PCB residues were significantly lower in female arctic terns than in male terns. Differences between the sexes were small in the herring gull. Thus it is possible that the female of the arctic tern is able to release pollutants, especially PCB residues, more effectively into eggs than the female of the herring gull. The biochemical mechanisms involved are not clear but a possible explanation may be different lipoprotein structures in the eggs of the species.