Rapid interphase analysis for prenatal diagnosis of translocation carriers using subtelomeric probes

Interphase fluorescence in situ hybridization (FISH) has become an accepted laboratory technique for the rapid and preliminary prenatal assessment of chromosome aneuploidy. The introduction of subtelomeric FISH probes now allows for the molecular–cytogenetic analysis of terminal chromosome rearrangements. In a prospective study, we examined the prenatal use of subtelomeric probes on interphase cells to rapidly detect the carrier status of a fetus when a parent carried a known reciprocal or Robertsonian chromosome translocation. Three of the cases were identified as being abnormal. All cases were confirmed by routine cytogenetic analysis. These findings clearly demonstrated the utility of this technique and these probes to rapidly and correctly identify balanced and unbalanced chromosome anomalies of a fetus that could result from parental translocations. Copyright © 2002 John Wiley & Sons, Ltd.     

Is there a correlation between the number of mutagens and the number of nonmutagens in an environmental sample?

We have adapted a procedure which was developed for studying the correlations in the distribution of genetic factors, such as sex ratios in siblings, to obtain estimates of the correlation between the number of mutagens and the number of nonmutagens in a sample. Positive correlations with correlation coefficients in excess of 0.8 were obtained. The high correlation suggests that it is possible to estimate the number of mutagens in samples with N > 100 compounds as (0.064 ± 0.01) N.     

Feed utilisation and growth in juveniles of Labeo rohita under the stress of endosulfan

The objective of the present study is to evaluate the nutrition and growth of Labeo rohita under the sublethal stress of endosulfan. It has been observed that the feed utilisation and growth were inferior in the fish under the stress of the toxicant. It was more so in the test fish under the influence of higher sublethal concentration. The food conversion ratio was higher suggesting that the nutrients are wasted.     

The role of condensed organic matter in the nonlinear sorption of hydrophobic organic contaminants by a peat and sediments

This study examines the effect of soil organic matter heterogeneity on equilibrium sorption and desorption of phenanthrene, naphthalene, 1,3,5-trichlorobenzene (1,3,5-TCB), and 1,2-dichlorobenzene (1,2-DCB) by soils and sediments. Two estuary sediments, a Pahokee peat (PP; Euic, hyperthermic Lithic Haplosaprist), and two subsamples (base- and acid-treated peat [TP] and acid-treated peat [FP]) of the peat were used as the sorbents. The contents of black carbon particles were quantified with a chemical extraction method. Petrographical examinations revealed the presence of the condensed soil and sediment organic matter (SOM) in Pahokee peat. The Freundlich isotherm model in two different forms was used to fit both sorption and desorption data. The results show that the sorption and desorption isotherms are generally nonlinear and that the apparent sorption-desorption hysteresis is present for phenanthrene and TCB. Detailed analysis of sorption data for the tested sorbent-sorbate systems indicates that black carbon is probably responsible for sorption isotherm nonlinearity for the two sediments, whereas the humic substances and kerogen may play the dominant role in nonlinear sorption by the peat. This investigation suggests that the microporosity of SOM is important for the hydrophobic organic contaminant (HOC) sorption capacity on the peat.     

Risk assessment and pathway study of arsenic in industrially contaminated sites of Hyderabad: a case study

Different areas in the industrial region of Patancheru near Hyderabad, Andhra Pradesh (A.P), India are contaminated with high concentration of arsenic, which is attributed to industrial source like veterinary chemicals, pharmaceuticals, pesticide industries, etc. Fourteen villages of this area of Patancheru were assessed for arsenic contamination by collecting samples of water (surface and ground), soil, fodder, milk, and vegetables. The total arsenic content in the whole blood, urine, hair, and nails of the residents showing arsenical skin lesions and other clinical manifestations were also studied. To understand the bioavailability of arsenic in this environment and its possible entry into human food chain, speciation studies of arsenic was carried out and the results are presented in this paper.     

Evaluation of Selected Gaseous Halocarbons for Use in source Test Performance Audits

A repository of 38 gaseous organic compounds in compressed gas cylinders has been established by EPA. This repository was established to provide standards for source test performance audits, that is, quantitative quality assurance tests. Among these compounds are ten halogenated organic species, which are the focus of this paper.

Stability studies of all ten compounds have been performed to determine the feasibility of using them as performance audit standards. Results indicate that all of the halocarbons tested are adequately stable to be used as reliable audit standards.

Subsequent to completion of stability studies, four of the ten halocarbons were used in source test performance audits. Results are available at this time for two of the four compounds; the results show agreement within 10% of the concentrations previously established by Research Triangle Institute.     

Recycling municipal incinerator fly- and scrubber-ash into fused slag for the substantial replacement of cement in cement-mortars

Fly- and scrubber-ash (weight ratio of approximately 1:3) from municipal solid waste incinerators (MSWI) are a major land-fill disposal problem due to their leaching of heavy metals. We uniformly mixed both types of ash with optimal amounts of waste glass frit, which was then melted into a glassy slag. The glassy slag was then pulverized to a particle size smaller than 38 μm for use as a cement substitute (20–40% of total cement) and blended with sand and cement to produce slag-blended cement-mortar (SCM) specimens. The toxicity characteristics of the leaching procedure tests on the pulverized slag samples revealed that the amount of leached heavy metals was far below regulatory thresholds. The compressive strength of the 28-day cured SCM specimens was comparable to that of ordinary Portland cement mortars, while the compressive strength of specimens cured for 60 or 90 days were 3–11% greater. The observed enhanced strength is achieved by Pozzolanic reaction. Preliminary evaluation shows that the combination of MSWI fly- and scrubber-ash with waste glass yields a cost effective and environmentally friendly cement replacement in cement-mortars.     

Seasonal Variation of Toxic Benzene Emissions in Petroleum Refinery

Petroleum refineries are largest chemical industries that are responsible for the emission of several pollutants into the atmosphere. Benzene is among the most important air pollutants that are emitted by petroleum refineries, since they are involved in almost every refinery process. Volatile organic compounds (VOCs) are a major group of air pollutants, which play a critical role in atmospheric chemistry. These contribute to toxic oxidants, which are harmful to ecosystem, human health and atmosphere. The variability of pollutants is an important factor in determining human exposure to these chemicals. The ambient air concentrations of benzene were measured in several sites around the Digboi petroleum refinery, near the city of Gowahati in northeast India, during winter and summer 2004. The seasonal and spatial variations of the ambient air concentrations of this benzene were investigated and analyzed. An estimation of the contribution of the refinery to the measured atmospheric levels of benzene was also performed. The ambient air mixing ratios of benzene in a large area outside the refinery was generally low, in ppbv range, much lower than the ambient air quality standards. This article presents the temporal and spatial variation of air pollution in and around petroleum refinery and showed that no health risk due to benzene is present in the areas adjacent to the refinery.     

Measurement of particulate phase polycyclic aromatic hydrocarbon (PAHs) around a petroleum refinery

A study on concentrations of ambient particulates viz. total suspended particulate matters (TSP), respirable suspended particulate matter (RSPM) and polycyclic aromatic hydrocarbons (PAH) were carried out at six sites around the Asia’s largest, 12 MMTPA, petroleum refinery in west coast of India. PAH concentrations are correlated with each other in these sites, suggesting that they have related sources and sinks. The present article discusses the monitoring aspects such as sample collection, pretreatment and analytical methods and compares the monitored levels for assessing the source receptor distribution pattern. The main sources of RSPM and PAHs in urban air are automobile exhaust (CPCB, Polycyclic aromatic hydrocarbons (PAHs) in air and their effects on human health. “”, 2003; Manuel et al., Environmental Science and Technology, 13: 227–231, 2004) and industrial emissions like petroleum refinery (Vo-Dinh, Chemical analysis of polycyclic aromatic hydrocarbons, Wiley: New York, 1989; Wagrowaski and Hites, Environmental Science and Technology, 31: 279–282, 1997). Polycyclic aromatic hydrocarbons (PAH) are ubiquitous constituents of urban airborne particulate mostly generated by anthropogenic activities (Li et al., Environmental Science and Technology, 37:1958–2965, 2003; Thorsen et al., Environmental Science and Technology, 38: 2029–2037, 2004; Ohura et al., Environmental Science and Technology, 32: 450–455, 2004) and some of them are of major health concern mainly due to their well-known carcinogenic and mutagenic properties (Soclo et al., Marine Pollution Bulletin, 40: 387–396, 2000; Chen et al., Environment International, 28: 659–668, 2003; Larsen and Baker, Environmental Science and Technology, 32: 450–455, 2003). Limited information is available on PAHs contributions from refineries to ambient air. Hence this study would not only create a database but also provide necessary inputs towards dose-response relationship for fixing standards. Also, since it acts as precursor to green house gas, the data would be useful for climate change assessments. The objective of this article is to find out the concentration of PAHs in particulate matter around petroleum refinery and compare with their concentrations in major Indian urban centers.     

Beryllium-7 Measurements in the Houston and Phoenix Urban Areas: An Estimation of Upper Atmospheric Ozone Contributions

Abstract

Natural radionuclides have been proposed as a means of assessing the transport of ozone (O₃) and aerosols in the troposphere. Beryllium-7 (⁷Be) is produced in the upper troposphere and lower stratosphere by the interaction of cosmogenic particles with atmospheric nitrogen and oxygen. ⁷Be has a 53.29-day half-life (478 keV γ) and is known to attach to fine particles in the atmosphere once it is formed. It has been suggested that O₃ from aloft can be transported into rural and urban regions during stratospheric–tropospheric folding events leading to increased background levels of O₃ at the surface. ⁷Be can be used as a tracer of upper atmospheric air parcels and the O₃ associated with them. Aerosol samples with a 2.5-µm cutoff were collected during 12-hr cycles (day/night) for a 30-day period at Deer Park, TX, near Houston, in August– September of 2000, and at Waddell, AZ, near Phoenix, in June–July of 2001. A comparison of ⁷Be levels with 12-hr O₃ averages and maxima shows little correlation. Comparison of nighttime and daytime O₃ levels indicate that during the day, when mixing is anticipated to be higher, the correlation of ⁷Be with O₃ in Houston is approximately twice that observed at night. This is consistent with mixing and with the anticipated loss of O₃ by reaction with nitric oxide (NO) and dry deposition. At best, 30% of the O₃ variance can be explained by the correlation with ⁷Be for Houston, less than that for Phoenix where no significant correlation was seen. This result is consistent with the intercept values obtained for ⁷Be correlations with either O₃ 24-hr averages or O₃ 12-hr maxima and is also in the range of the low O₃ levels (25 ppb) observed at Deer Park during a tropical storm event where the O₃ is attributable primarily to background air masses. That is, maximum background O₃ level contributions from stratospheric sources aloft are estimated to be in the range of 15–30 ppb in the Houston, TX, and Phoenix, AZ, area, and levels above these are because of local tropospheric photochemical production.