Sources of high PM2.5 concentrations in Milan, Northern Italy: molecular marker data and CMB modelling.

In Milan (MI), the largest city in Northern Italy, the annually average PM2.5 concentration is above 25 µg m(-3), the value that the EU established as a target for 2010, and the upper limit from 2015 onwards (2008/30/CE). Over a three-year period (2006-2009) PM concentrations and chemical compositions were measured in an urban site (MI), a rural site (OB) and a remote site (ASC) in Northern Italy. Chemical characterization (EC/OC, inorganic ions, elements, C20-C32 n-alkanes, C2-C5 mono and dicarboxylic acids, levoglucosan and PAHs) was carried out on PM2.5 samples from the three sites, and PM10 from MI. Molecular markers were used in Chemical Mass Balance (CMB) modelling to estimate the contributions of primary sources to OC, and then PM mass from each source was reconstructed in MI, OB and ASC for different seasons. Estimates of the traffic (TR) source contribution to PM2.5 mass ranged from 4.1 (± 2.0) µg m(-3) during the summer, to 13.3 (± 6.7) µg m(-3) during the winter in MI. TR was the main primary source for PM2.5 concentrations in MI (17-24%). Its contribution was lower at the OB site (7-9%) and at the remote ASC site (3-4%). TR is a local source, while biomass burning (BB) is a diffuse regional source in Northern Italy: during fall and winter, BB was 25-30% and 27-31% of PM2.5 at MI and OB respectively. Other primary sources accounted for a small amount of the PM2.5, i.e. natural gas combustion (0-1%), plant debris (0-4%), road dust (RD=0-4%; but 15% at ASC during winter and 10% of PM10 at MI during summer) and sea salt (0-1%). Secondary inorganic+organic aerosol constituted the major part of the PM2.5 mass during spring and summer (50-65%) at the three sites.

Vertical distribution of hydrocarbons in the low troposphere below and above the mixing height: tethered balloon measurements in Milan, Italy.

A novel approach for measuring vertical profiles of HCs and particle number concentrations was described and applied in the low troposphere over Milan (Italy) during typical spring and summer days. Particle profiles yielded nearly homogeneous concentrations below the mixing height, with level-to-ground concentration ratios of 92-97%, while HCs showed a more pronounced decrease (74-95%). Vertical mixing and photochemical loss of HCs were demonstrated to cause these gradients. Much lower concentrations were observed for the profiles above the mixing height, where the HC mixtures showed also a different composition, which was partially explained by the horizontal advection of air with HC sources different to those prevailing at the site. The application of pseudo-first order kinetics for reactions between HCs and the hydroxyl radical allowed for the estimation of the vertical mixing time scale in the order of 100 ± 20 min.

Semicontinuous GC analysis and receptor modelling for source apportionment of ozone precursor hydrocarbons in Bresso, Milan, 2003.

The European Ozone Directive 2002/3/EC specifies the analysis of 30 individual C2-C9 hydrocarbons in urban air with the attribution of emission sources to pollution concentrations as a major objective. In the present study, we investigate an approach for source apportionment of these ozone precursor hydrocarbons in urban air based on reliable semi continuous volatile organic compound (VOC) analysis in the field and in vehicle emission laboratory combined with multivariate receptor modeling. The GC system relies on an hourly analytical cycle based on a trap sample enrichment phase followed by a dual column gas chromatographic flame ionisation detector (FID) analysis and has successfully been tested during an air monitoring campaign at an urban site (Milan, Italy, September 2003) and in the vehicle laboratory performing exhaust emission measurements while running driving cycles on a chassis dynamometer (mopeds, gasoline and diesel cars). The receptor modeling relies on two complementary principles. The chemical mass balance (CMB) modeling apportions well characterized source profiles for the 30 individual C2-C9 hydrocarbons in the Ozone Directive to the concentrations in ambient air and produces source contribution estimates (SCE) as output. The positive matrix factorization (PMF) analyses variability in the ambient air concentration data and searches for latent variables consisting of co-varying hydrocarbons and produces profiles as output, which in this study could be attributed to known emission sources. Both CMB and PMF rely on an estimated uncertainty for each input data. A new approach is presented, by which the uncertainty is allowed to float as function of the photochemical reactivity of the atmosphere and the stability of each individual compound.

Fragmentation pathways of organoarsenical compounds by electrospray ion trap multiple mass spectrometry (MS6).

With its detection limit well below 30 pg microl(-1) LC-MS-MS has become a sensitive and thus popular analytical technique for organoarsenical compounds. Collision induced dissociation (CID) is a valuable tool for speciation and facilitates a positive identification of the species detected. However, it is not straightforward to understand the fragmentation pathways of organoarsenical compounds when only CID-MS-MS data is available. In the present paper we have investigated multiple mass spectrometry (MSn, n=1, 2, 3, 4, 5, 6) with electrospray CID fragmentation for a number of organoarsenical compounds likely to occur in the environment. The investigated compounds were tetramethylarsonium, trimethylarsinoxide, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, arsenocholine, and dimethylarsinoylethanol. By CID of (protonated) organoarsenical cations mostly even-electron fragments are produced after neutral loss processes such as elimination of H2, H2O, CH4, C2H2, C2H4, C2H6, HCHO, CH3OH, C2H5OH, C2H4O, and CH2CO. However, abundant odd-electron fragments are also formed after elimination of radical species. Evidence for reduction of As(V) to As(III) as a driving force in the odd-electron ion formation is obtained.

Atmospheric pressure ionisation multiple mass spectrometric analysis of pesticides.

Liquid chromatography-multiple mass spectrometry (LC-MS") has been investigated for analysis of polar pesticides in water using an ion-trap instrument and atmospheric pressure ionisation. Carbamate, triazine and phenylurea pesticides were best ionised as positive ions with atmospheric pressure chemical ionisation, while phenoxy acid herbicides, nitrophenols and bentazone yielded stronger signals as negative ions with pneumatically assisted electrospray. The ion fragmentation processes and pathways were studied in detail by MS, MS2, MS3 and MS4. All compounds were observed as their protonised or deprotonised molecular ions by MS and in the successive fragmentation by MS" the structures of typical (diagnostic) product ions were tentatively identified for each class of pesticide. Phenylureas yield an ion at m/z 72 by MS2, corresponding to O=C=N+(CH3)2. Carbamates produce [M+H-CONCH3]+ fragments by MS2 from neutral loss of methylisocyanate. Characteristic fragmentation pathways for triazine pesticides are [M+H]+-->m/z 174-->m/z 146-->m/z 110 and [M+H]+-->m/z 174-->m/z 132-->m/z 104 by MS-MS2-MS3-MS4 from cleavage of lateral chains in the triazine ring followed by ring opening. Phenoxy acid herbicides produce peculiar fragments by MS2 from loss of the acidic group possibly as the corresponding lactone. Nitrophenols are subject to loss of both *OH radical and NO groups thereby forming the correspondent phenols and quinones. The performance of the method with respect to quantitation compares favourably with traditional methods. With the ion-trap run in a time scheduled single ion monitoring mode, typical limits of detection (LODs) are in the low pg range and the repeatability standard deviations are between 3 and 15%. Assuming extraction of 1-l water samples and 1 ml final volumes the injection of 50-microl aliquots corresponds to LODs well below the requirement for the European Union water directive (EC/80/778).

Surfactant solubilization of hydrophobic compounds in soil and water : II. The role of dodecylsulphate-soil interactions for hexachlorobenzene.

The soil/water partition coefficient (Kd) of hexachlorobenzene (HCB) ranged from 220 1/kg to 1800 1/kg for eight soils having a wide range of physico-chemical properties. Kd normalised to soil organic carbon (Koc) was found to be 28000 ± 4800 1/kg. Anionic surfactant dodecylsulphate (DS) present at concentrations above the critical micellar concentration (CMC) caused reductions in the apparent soil/water partition coefficient (Kd (*)) in the range of 3-26 times for most soils and up to 36-91 times for sandy soils. Below CMC, at environmentally relevant surfactant concentrations, Kd (*) was reduced by a factor of 1-13. For clay and calcareous soils significant adsorption/complexation/precipitation of DS occurred. At the lowest DS concentration this produced a two-fold increase in Kd (*). At increasing DS concentrations this effect was shielded by the solubihzing effect from DS. Monomer (Kmn) and micellar (Kmc) surfactant/water partition coefficients for HCB were determined to be, 980 ± 190 1/kg and 21000 ± 1600 1/kg, respectively.

Decomposition of Terpenes by Ozone during Sampling on Tenax.

The ozonolytic decomposition of terpenes and terpenoids during sampling on Tenax is investigated in an artificial air system at ambient concentration levels. The detrimental effect of 8-150 ppbv ozone depends on the chemical structure of the compounds: saturated terpenoids such as 1,8-cineole, camphor, and bornyl acetate are unaffected by ozone. The terpenes and terpenoids which containing one C-C double bond are slightly decomposed in the order camphene < ß-pinene ≈ myrtenal < α-pinene < sabinene ≈ citronellal. The compounds containing two or more double bonds are significantly decomposed in the order d-limonene ≈ citral < linalool < ß-ocimene < terpinolene << α-terpinene ≈ ß-caryophyllene. For α-pinene, sabinene and d-limonene, their ozonolysis products are found on the tubes: pinonaldehyde, 5-(1-methylethyl)bicyclo[3.1.0]hexan-2-one, and 3-(1-methylethenyl)-6-oxoheptanal. The analytical recoveries are significantly enhanced for many compounds when the sampling duration is reduced from 10 min to 30 s, explained by the time available for ozonolysis. A miniature ozone scrubber with multiple layers of MnO(2)-coated copper nets was developed and thoroughly tested. The optimal number of plies is found to be 8, which ensures quantitative recoveries for all test compounds except α-terpinene, ß-caryophyllene, citral, and citronellal. The results that are reported here call into question previous data on terpenes and terpenoids and/or their oxidation products where measurements have been carried out without the prior removal of ozone.

Toxic PCB congeners and organochlorine pesticides in Italian human milk.

Human milk from four major Italian cities was analyzed for individual congeners of polychlorinated biphenyls (PCB), DDT, DDE, hexachlorobenzene, and beta-hexachlorocyclohexane. Minimum and maximum concentrations in milk from individual mothers for most compounds ranged between one order of magnitude below and above the mean value of all mothers. Good agreements were found between results from pooled samples and mean values of individual samples. No statistically significant difference between cities was found and the levels in milk from Italian mothers did not differ significantly from published levels from other parts of the world. Principal component analyses revealed that the PCB congener distribution pattern was very similar in all mothers, independent of location. Average concentrations in milk from the four cities were 19(+/- 5) micrograms liter-1 total PCB or 3.2(+/- 0.8) ng liter-1 toxicity equivalents according to the most conservative TCDD toxicity equivalent factors of PCBs proposed in the literature, 70(+/- 18) micrograms liter-1 DDE, 4.5(+/- 1.2) micrograms liter-1 DDT, 5.6(+/- 1.9) micrograms liter-1 HCB, and 4.4(+/- 1.7) micrograms liter-1 beta-hexachlorocyclohexane.

Surfactant solubilization of hydrophobic compounds in soil and water : I. Dodecylsulphate monomer and micellar partition coefficients for 28 polychlorinated biphenyls (PCBs) [41].

Reductions in the apparent soil-water partition coefficients (Kd (*)) for 28 polychlorinated biphenyls (PCBs) caused by the surfactant sodium dodecylsulphate (SDS) in the aqueous phase were studied. Above the critical micelle concentration (CMC) of the surfactant, Kd (*) was reduced by 2-3 orders of magnitude, but even far below CMC at environmentally relevant surfactant concentrations significant reductions in Kd (*) were observed. The plot of the soil-water partition coefficient (Kd) divided by Kd (*) versus the concentration of SDS allowed for the calculation of monomer (Kmn (oc)) and micellar (Kmc (oc)) surfactant-water partition coefficients normalized to organic carbon for each PCB congener. Kmn (oc) values were comparable with published values for the partition of PCBs between natural dissolved organic matter and lake water. Kmc (oc) values were up to 30 times higher than Kmn (oc) values and comparable with published octanol-water distribution coefficients. The findings of the present study underline the potential of surfactants at concentrations below their CMC to mobilize otherwise strongly bound hydrophobic compounds in soil-water systems.

Soil sorption of 20 PCB congeners and six chlorobenzenes.

The soil sorption of six chlorobenzenes and 20 PCB congeners was studied by allowing aqueous trace solutions (ppb) of transformer fluids to equilibrate with 3-6 different soils. Linear relations were found between distribution constants and soil organic carbon content. Sorption was favored by a high degree of chlorination and the absence of ortho-substitution in the biphenyl. Sorption kinetics seemed to be first-order controlled (two steps) with rate constants in the order of many hours. We present correlations between sorption data and published physical data, which will be useful for modeling the transport and the fate of PCBs and chlorobenzenes in the environment.

Prolactin cell activity in female and male Syrian hamsters: an apparent sexually dimorphic response to light deprivation and pinealectomy.

In order to determine the role of the pineal gland in mediating the effects of long-term light deprivation on prolactin (PRL) cell activity in a highly photosensitive species, PRL synthesis, storage and release were determined in both female and male Syrian hamsters that were either blind, blind and pinealectomized or left intact for 14 weeks. PRL release was determined in vivo by measuring the amount of immunoreactive (RIA) PRL in the serum of the animals in each group with a heterologous RIA for hamster PRL. Binding resulted in a 98 and 88% reduction in serum PRL levels in female and male hamsters, respectively. Pinealectomy largely prevented the suppressive effects of blinding on PRL release; however, PRL levels in blind pinealectomized animals were intermediate between those in intact and blind animals. PRL synthesis was evaluated by assessing the amount of 3H-leucine incorporated into PRL by anterior pituitaries in vitro. In female hamsters 14 weeks of light deprivation resulted in an 87% decrease in the incorporation of 3H-leucine into newly synthesized PRL whereas in males only a 40% reduction occurred. While pinealectomy completely prevented the inhibitory effects of blinding on PRL synthesis in males, it was less effective in female hamsters inasmuch as PRL synthesis was still nearly 50% lower in blind pinealectomized animals than in controls. Stored PRL, as represented by the total amount of RIA-PRL in vitro, was 96% lower in blind female hamsters as compared with intact controls; in blind male hamsters, stored PRL was reduced by 77%.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of simulated acid rain and (+/-)-2-(2,4-dichlorophenoxy) propanoic acid on selected crops.

The effect of foliar-applicated (+/-)-2-(2,4-dichlorophenoxy)propanoic acid (2,4-DP) under simultaneous influence of simulated acid rain at pH levels of 3.3, 4.3, and 5.6 was examined for young plants of white mustard, rape, cress, lettuce, radish, carrot, oat, and barley grown in climate chambers. After 1-2 weeks with daily showers plants received a single foliar application of 2,4-DP in aqueous solution (500 microliter; 0.25-50.0 mg X liter-1). After a post-treatment period of 2-3 weeks with daily showers the plants were sampled. 2,4-DP at 5 mg X liter-1 or higher concentrations caused various symptoms for the dicotyledons. Monocotyledons and carrot remained unaffected. The application of acid rain at pH 3.3 produced morphological changes, increased the symptoms from 2,4-DP, and reduced the dry weight and the leaf to stem ratio. Cress exposed only to acid rain showed necrotic spots and chlorosis at pH 3.3. By decreasing pH taller plants with smaller leaves were observed. The combined effect of acid rain and 2,4-DP was additive rather than synergistic.

Alteration of seizures resulting from pinealectomy in the rat after neonatal treatment with 6-hydroxydopamine.

Convulsions from combined pinealectomy and parathyroidectomy were examined in rats treated as neonates with 6-hydroxydopamine (6-OHDA). Injection of 6-OHDA caused a significant reduction in the average latency to onset of clonic-tonic convulsions. Moreover, of the 6-OHDA-treated rats which convulsed, nearly half of them died during a seizure. In sham-pinealectomized rats, neonatal treatment with 6-OHDA reduced norepinephrine (NE) and increased dopamine levels in the forebrain while brainstem levels of NE were increased. Pretreatment with desmethylimipramine reversed the effects of 6-OHDA on convulsions and catecholamine levels. The results indicate that catecholamine lesions with 6-OHDA exacerbate convulsions from pinealectomy.

Estrogen sulfoconjugation by human endometrial cancer cells (RL95-2) in culture.

Estrogen metabolism was studied in a newly established cell line (RL95-2) derived from a human endometrial carcinoma. Estradiol and estrone were metabolized to water-soluble derivatives by cells under in vitro culture conditions. Between 80-90% of the added steroids were metabolized, with nearly quantitative recovery of the products from the incubation medium. Arylsulfatase treatment converted the metabolites to ether-soluble forms, whereas beta-glucuronidase had no effect on the aqueous solubility of these compounds. Butanol extracts of the water-soluble estradiol metabolites cochromatographed on high performance liquid chromatography with 17 beta-estradiol-3-sulfate (93.6%) or estrone-3-sulfate (3.5%). No more than 6% of the estradiol added to the incubation medium was recovered in the form of estrone, either as estrone or estrone sulfate. After arylsulfatase treatment of the estradiol conjugates, 92% of the ether-soluble radioactivity cochromatographed with estradiol, and 3.8% cochromatographed with estrone. Estrogen-sulfurylating activity was localized in the cytosol of subcellular fractions of RL95-2 cells. The sulfoconjugation of estrogens by RL95-2 cells may prove useful as a model for the investigation of estrogen metabolism in endometrial carcinoma cells.

Preliminary results--isolation and identification of pineal neurohypophysial hormone-like activity.

We have initiated a project designed to isolate and identify the neurohypophysial peptides found in the bovine pineal gland. Our principle interest is to provide definitive molecular evidence in order to eliminate the conflict created by the present literature as to the presence of arginine vasotocin in the mammalian pineal gland. The pineals were extracted and chromatographed according to standard methods for the isolation of neurohypophysial peptides. All fractions were assayed for their ability to cause milk ejection using the in vivo assay described by Hadley et al. (1975). However, during the course of the isolation procedure a partially purified fraction was isolated that showed neurohypophysial hormone-like activity. According to tests run on parallel chromatographic columns, the substance responsible for the neurohypophysial hormone-like activity could not be oxytocin, arginine vasotocin or arginine vasopressin.

A rapid method for taurine quantitation using high performance liquid chromatography.

Presented is a fluorometric technique for the quantitative analysis of taurine in biological samples. The sample is homogenized, treated with picric acid, and passed through a mixed-bed, ion-exchange column. The eluant is lyophilized, reconstituted, and an aliquot derivatized with o-phthalaldehyde (OPA) prior to high performance liquid chromatography (HPLC). The ion-exchange column removes all amino acids, cysteic acid, phosphoethanolamine, and hypotaurine while allowing quantitative recovery of taurine. Using the procedure as outlined, quantitation has been performed from 0.080-1.6 nmoles per analysis. The lower limit of quantitation, using the equipment specified, was shown to be 5 pmoles per analysis. The method allows rapid sample processing while maintaining a high degree of sensitivity and accuracy.