Ranking REACH registered neutral, ionizable and ionic organic chemicals based on their aquatic persistency and mobility.

The contaminants that have the greatest chances of appearing in drinking water are those that are mobile enough in the aquatic environment to enter drinking water sources and persistent enough to survive treatment processes. Herein a screening procedure to rank neutral, ionizable and ionic organic compounds for being persistent and mobile organic compounds (PMOCs) is presented and applied to the list of industrial substances registered under the EU REACH legislation as of December 2014. This comprised 5155 identifiable, unique organic structures. The minimum cut-off criteria considered for PMOC classification herein are a freshwater half-life >40 days, which is consistent with the REACH definition of freshwater persistency, and a log Doc < 4.5 between pH 4-10 (where Doc is the organic carbon-water distribution coefficient). Experimental data were given the highest priority, followed by data from an array of available quantitative structure-activity relationships (QSARs), and as a third resort, an original Iterative Fragment Selection (IFS) QSAR. In total, 52% of the unique REACH structures made the minimum criteria to be considered a PMOC, and 21% achieved the highest PMOC ranking (half-life > 40 days, log Doc < 1.0 between pH 4-10). Only 9% of neutral substances received the highest PMOC ranking, compared to 30% of ionizable compounds and 44% of ionic compounds. Predicted hydrolysis products for all REACH parents (contributing 5043 additional structures) were found to have higher PMOC rankings than their parents, due to increased mobility but not persistence. The fewest experimental data available were for ionic compounds; therefore, their ranking is more uncertain than neutral and ionizable compounds. The most sensitive parameter for the PMOC ranking was freshwater persistency, which was also the parameter that QSARs performed the most poorly at predicting. Several prioritized drinking water contaminants in the EU and USA, and other contaminants of concern, were identified as PMOCs. This identification and ranking procedure for PMOCs can be part of a strategy to better identify contaminants that pose a threat to drinking water sources.

The presence and leachability of antimony in different wastes and waste handling facilities in Norway.

The environmental behaviour of antimony (Sb) is gathering attention due to its increasingly extensive use in various products, particularly in plastics. Because of this it may be expected that plastic waste is an emission source for Sb in the environment. This study presents a comprehensive field investigation of Sb concentrations in diverse types of waste from waste handling facilities in Norway. The wastes included waste electrical and electronic equipment (WEEE), glass, vehicle fluff, combustibles, bottom ash, fly ash and digested sludge. The highest solid Sb concentrations were found in WEEE and vehicle plastic (from 1238 to 1715 mg kg(-1)) and vehicle fluff (from 34 to 4565 mg kg(-1)). The type of acid used to digest the diverse solid waste materials was also tested. It was found that HNO3:HCl extraction gave substantially lower, non-quantitative yields compared to HNO3:HF. The highest water-leachable concentration for wastes when mixed with water at a 1 : 10 ratio were observed for plastic (from 0.6 to 2.0 mg kg(-1)) and bottom ash (from 0.4 to 0.8 mg kg(-1)). For all of the considered waste fractions, Sb(v) was the dominant species in the leachates, even though Sb(iii) as Sb2O3 is mainly used in plastics and other products, indicating rapid oxidation in water. This study also presents for the first time a comparison of Sb concentrations in leachate at waste handling facilities using both active grab samples and DGT passive samples. Grab samples target the total suspended Sb, whereas DGT targets the sum of free- and other chemically labile species. The grab sample concentrations (from 0.5 to 50 µg L(-1)) were lower than the predicted no-effect concentration (PNEC) of 113 µg L(-1). The DGT concentrations were substantially lower (from 0.05 to 9.93 µg L(-1)) than the grab samples, indicating much of the Sb is present in a non-available colloidal form. In addition, air samples were taken from the chimney and areas within combustible waste incinerators, as well as from the vent of WEEE sorting facility. The WEEE vent had the highest Sb concentration (from <100 to 2200 ng m(-3)), which were orders of magnitude higher than the air surrounding the combustible shredder (from 25 to 217 ng m(-3)), and the incinerator chimney (from <30 to 100 ng m(-3)). From these results, it seems evident that Sb from waste is not an environmental concern in Norway, and that Sb is mostly readily recovered from plastic and bottom ash.

The sorption and desorption of phosphate-P, ammonium-N and nitrate-N in cacao shell and corn cob biochars.

The sorption of PO4-P, NH4-N and NO3-N to cacao shell and corn cob biochars produced at 300-350°C was quantified. The biochars were used; (i) as received (unwashed), (ii) after rinsing with Millipore water and (iii) following leaching with Millipore water. In addition to sorption, desorption of PO4-P from the unwashed biochars was quantified. There was no sorption of PO4-P to either washed or rinsed biochars, but following leaching, both biochars adsorbed PO4-P and distribution coefficients (Kd L kg(-1)) were very similar for both materials (10(1.1±0.5) for cacao shell biochar and 10(1.0±0.2) for corn cob biochar). The BET surface area and micropore volume increased 80% and 60% for the cacao shell and corn cob biochars following leaching. After 60 d, 1483±45 mg kg(-1) and 172±1 mg kg(-1) PO4-P was released from the cacao shell and corn cob biochars. NH4-N was sorbed by both unwashed biochars, albeit weakly with Kd values around 10(2) L kg(-1). We speculate that NH4-N could bind via an electrostatic exchange with other cationic species on the surface of the biochar. There was no significant release or sorption of NO3-N from or to either of the biochars.

Lifetime of the 6793-keV state in 15O.

The energy derived from the CN cycle at low stellar temperatures is regulated by the 14N(p,gamma)15O reaction. A previous direct measurement of this reaction has been interpreted as showing evidence for a subthreshold resonance which makes a major contribution to the reaction rate at low temperatures. This resonance, at E(c.m.) = -504 keV would correspond to the known Ex = 6793-keV state in 15O. We have measured a mean lifetime of 1.60(+0.75)(-0.72) fs (90% C.L.) for this state using the Doppler-shift attenuation method. This lifetime is a factor of 15 longer than that inferred from the (p,gamma) data and implies that the contribution of the subthreshold resonance is negligible.

Cardiac missiles. A review of the literature and personal experience.

The management of retained missiles in the heart is still controversial. In an attempt to define the issue more clearly, the reported cases in the English literature from 1940 to 1988 (group 1) and our experience from 1968 to 1988 (group 2) were reviewed. In group 1 there were 222 missiles retained in the hearts of 201 patients. The retained missiles were 45 bullets in 45 patients, 109 shrapnel in 99 patients, 18 pellets in 7 patients, and 50 unidentified missiles in 50 patients. Thirteen of the missiles were completely embedded intramyocardial missiles, 122 were partially intramyocardial, 47 were free in a cardiac chamber, and 40 were intrapericardial. One hundred four of the missiles were removed and 118 were left in place. In group 2 there were 24 missiles, 18 bullets, 1 bullet fragment, and 5 pellets retained in the hearts of 24 patients. Ten missiles were removed, no attempt was made in 13 patients, and an unsuccessful attempt was made to remove one other. From group 1 patients, 6 died, 2 with intracavitary missiles, 3 patients with partially intramyocardial, and 1 patient with an intrapericardial missile, all of whom had either unsuccessful or no attempt to remove the missile. Twenty-seven patients had symptoms, all of whom, except two, had either unsuccessful or no attempt to remove the missile. All group 2 patients did well and had been free of symptoms related to the missiles. This review suggests that the management of missiles in the heart should be individualized according to the patient's clinical course, the site, shape, and size of the missile, and that in selected patients missiles in the heart are tolerated well.

Missiles in the heart.

The records of 24 patients who had a missile retained in the heart and who were treated at Grady Memorial Hospital from 1968 to 1987 were reviewed. In 22, the missile lodged in the heart after its direct injury and in the remaining 2, after the bullet injured a systemic vein. Immediately after the cardiac injury, 7 of the 22 patients were seen with cardiac tamponade (3 also had hemothorax), 11 were seen with hemothorax, 5 were asymptomatic, and 1 was in shock. Seven patients underwent emergency thoracotomy; the bullet was removed in 3, but in the remaining 4 patients, it was not located. In the other 17 patients and in the 4 in whom the bullet could not be found during emergency thoracotomy, the diagnosis was suspected from the chest roentgenograms and confirmed by cardiac fluoroscopy or angiocardiography. Eight patients with retained bullets underwent elective operation; the bullet was removed from 7 and in 1 it was left embedded in the right ventricular septum. All 10 patients who underwent excision of the missile recovered without complication except 1 in whom pericarditis developed, and all were followed for up to 17 years. All 14 patients with a retained missile in the heart had no cardiac symptoms referable to the bullet and were followed for up to 15 years. This experience suggests that the management of patients with a bullet of .38 caliber or smaller that is retained in the heart should be individualized according to the patient's clinical course and the site of the bullet and that in select patients, bullets left in the heart are tolerated well.

Rabbit lung flavin-containing monooxygenase. Purification, characterization, and induction during pregnancy.

A flavin-containing monooxygenase has been purified to apparent homogeneity from lung microsomes of pregnant rabbits and characterized with respect to a number of physical and catalytic parameters. The apparent molecular weight, as determined on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was 59,000, and the lung microsomal flavoprotein was shown to contain 14 nmol of FAD/mg of protein. Addition of NADP+ to the oxidized flavoprotein produced a shift in the spectrum characteristic of the flavin-containing monooxygenase from porcine liver, and addition of small amounts of NADPH to the oxidized rabbit lung enzyme produced a stable spectral intermediate consistent with that of a 4a-peroxyflavin. Rabbit lung flavin-containing monooxygenase differed markedly from the porcine liver enzyme in exhibiting a broader pH optimum from 8.5-10.5, by not being inhibited by concentrations of sodium cholate as high as 1% and by withstanding, in the absence of NADPH, incubation at 45 degrees for at least 10 min with no significant loss of activity. Unlike the pig liver enzyme, purified rabbit lung enzyme was not activated by n-octylamine and, in fact, n-octylamine stimulated NADPH oxidation. A number of compounds known to be substrates of the pig liver enzyme, including benzphetamine, chlorpromazine, and imipramine, are not substrates for the rabbit lung enzyme, whereas prochlorperazine and trifluoperazine are excellent substrates. Antibodies to rabbit lung flavin-containing monooxygenase were raised in guinea pig and utilized for the immunoquantitation of this enzyme throughout gestation. The activity (as determined by N,N-dimethylaniline-N-oxidation) and amount of rabbit lung flavin-containing monooxygenase were maximally induced (5-fold) on the 28th day of gestation. Liver microsomes from rabbit did not contain any of the lung form of flavin-containing monooxygenase at any time during gestation, as evidenced by results from Western blotting. These results demonstrate that, at least in rabbit, flavin-containing monooxygenase can exist as more than a single form. The physiological significance of the induction of this enzyme during pregnancy is not known.

A prostaglandin omega-hydroxylase cytochrome P-450 (P-450PG-omega) purified from lungs of pregnant rabbits.

Cytochrome P-450-dependent prostaglandin omega-hydroxylation is induced over 100-fold during late gestation in rabbit pulmonary microsomes (Powell, W.S. (1978) J. Biol. Chem. 253, 6711-6716). Purification of cytochromes P-450 from lung microsomes of pregnant rabbits yielded three fractions. Two of these fractions correspond to rabbit lung P-450I (LM2) and P-450II (LM5), which together constitute 70-97% of total cytochrome P-450 in lung microsomes from nonpregnant rabbits. The third form, which we designate rabbit cytochrome P-450PG-omega, regioselectively hydroxylates prostaglandins at the omega-position in reconstituted systems with a turnover of 1-5 min-1. Titration with purified pig liver cytochrome b5, demonstrated a 4-fold maximum stimulation at a cytochrome b5 to a P-450 molar ratio of 1-2. Rabbit lung P-450PG-omega formed a typical type I binding spectrum upon the addition of prostaglandin E1 with a calculated K8 of 1 microM, which agreed reasonably well with the kinetically calculated Km of 3 microM. Cytochrome P-450PG-omega was isolated as a low-spin isozyme with a lambda max (450 nm) in the CO-difference spectrum distinguishable from P-450I (451 nm) and P-450II (449 nm). Sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis demonstrated that although purified P-450PG-omega had a relatively low specific content (12.1 nmol mg-1), it appeared homogeneous with a calculated minimum Mr of 56,000, intermediate between rabbit LM4 and LM6. When lung microsomes from pregnant and nonpregnant rabbit were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, a protein band, with a Mr identical to P-450PG-omega, was observed in the pregnant rabbit, whereas this band appeared to be very faint or absent in microsomes from the nonpregnant rabbit. Purification of cytochromes P-450 from nonpregnant rabbit lung yielded only P-450I and P-450II. P-450PG-omega appears to be a novel rabbit P-450, possessing high activity towards omega-hydroxylation of prostaglandins, and is greatly induced during pregnancy in rabbit lung.

Rabbit lung flavin-containing monooxygenase is immunochemically and catalytically distinct from the liver enzyme.

Flavin-containing monooxygenase has been purified to homogeneity from lung microsomes of pregnant rabbits. Antibody to rabbit lung flavin-containing monooxygenase was raised in guinea pig. Ouchterlony double diffusion analysis with this antibody produced precipitin lines of identity with the purified rabbit lung enzyme and lung microsomes from pregnant and non-pregnant rabbits. No cross-reaction was seen with liver microsomes from rabbit or with purified pig liver enzyme. The tricyclic antidepressant drugs, imipramine and chlorpromazine, are not substrates for the rabbit lung enzyme, whereas they are rapidly oxidized by the pig liver enzyme. These results indicate that rabbit lung and liver flavin-containing monooxygenases differ in substrate specificity, are immunochemically distinct proteins, and may be different gene products.