Magnesium and the deposition of lead in the shell of three populations of the garden snail Cantareus aspersus

The loss of Pb from snail soft tissues may depend on the excretion of Ca, and involve the mobilization of shell Ca. Most sub-adults in three populations of Cantareus aspersus (syn. Cornu aspersum Müller) either failed to add, or lost, shell mass on a diet with 250 μg g⁻¹ Pb. Their failure to mineralize shell extensions occurred irrespective of food consumed, time or dietary Mg. Budgets of metals for 36 individuals in each of two populations showed that Ca loss would account for the reduction in shell mass. Lead concentrations were higher in the reduced shells but this may be a consequence of their smaller mass, rather than its cause. In both populations shell reduction correlated with the total mass of Pb assimilated. Any shell growth may have been dependent on the initial Ca reserve in each snail. Differential movement of Mg, Pb and Ca occurred between the shell and soft tissues.     

Prenatal diagnosis of thrombocytopenia absent radius syndrome by ultrasound and cordocentesis

The prenatal diagnosis of thrombocytopenia absent radius (TAR) syndrome, utilizing ultrasound and cordocentesis, is described. To our knowledge, this represents the first prenatal diagnosis of this condition in an index case. The diagnostic evaluation of a fetus with upper extremity limb reduction defects is discussed.     

Prenatal diagnosis of an intra-abdominal sacrococcygeal teratoma

The prenatal diagnosis of a presacral (type IV) sacrococcygeal teratoma (SCT) is described. The initial ultrasound appearance was suggestive of a lower urinary tract obstruction, but further ultrasonic examination and radiological imaging using contrast medium led to the diagnosis of SCT. This is the first prenatal diagnosis of a totally intra-abdominal SCT.     

Short-Term Nitrogen Dioxide Exposure and Acute Respiratory Disease in Children

A CHESS data base from Chattanooga, Tennessee was thoroughly scrutinized and found to be of high enough quality to warrant epidemiological analysis. Using this data base, the relationship between NO₂ ambient pollution levels and acute respiratory disease in children was examined. Although a statistically significant relationship was found, it was not monotonic. Indeed, over the range of pollution values experiences, more illness is associated with low pollution values than with high ones. A U-shaped relationship between illness and NO₂ concentrations was found in several subpopulations in addition to the entire data set, although for some subpopulations no relationship was found. In contrast, higher ambient sulfate levels were found to have a positive effect on acute respiratory disease incidence in children over the entire period and for different subsamples, although this effect was not significant for either season analyzed separately.     

Technician Training in Environmental Health Science

In colleges and universities across the country, courses in ecology and environmental science are among the newest additions to the catalog. The goal of such courses is to make students aware of the environmental dilemma, a just and necessary goal. However, there is a need to do more than this. Jobs dealing with environmental protection are becoming more and more complex due to the recent passage of State and Federal legislation, which includes the Clean Air Act, the Amendments to the Water Pollution Control Act and the Occupational Safety and Health Act, just to name a few. Trained personnel are needed by industry and government. For this reason, in 1971, Middlesex County College initiated an Environmental Health Science Technology Program.     

Control of Odors and Aerosols from Spent Grain Dryers

The information contained in this paper is directed to research workers concerned with odor identification and the development of methods for removal of odorous components from hot, moist stack gases and to application engineers faced with the practical problem of selecting effective, yet economical, odor control equipment for industrial operations. The new techniques described here demonstrate the beneficial uses of gas phase reactions as a conditioning step preceding absorption in a chemically reactive solution. Cost comparisons show markedly lower costs for full-scale reactor-absorbers than for gas incinerators for equal contaminant removal. Other methods of removing odors at the source, e.g., injection of ozone, use of nonvolatile oxidizing agents in solution, and adsorption on activated charcoal, were found to be impractical, ineffective, or both. The application of reactor-absorbers to spent grain drying is discussed in detail and reference is made to the use of this technique for other food industry waste treatment processes including rendering and fish and poultry meal production.     

Performance and Problems of Claus Plant Operation on Coke Oven Acid Gases

The application of Claus Plant sulfur recovery units to the coke oven gas (COG) acid gases at three Bethlehem Steel Corporation plants is discussed. While many of the problems encountered are not unique to coke oven gas-derived acid gases, it was found that special consideration must be given to the effect of components not normally encountered in the typical Claus plant application to petroleum derived gases. It is perhaps fortunate that the feed composition to the three units was sufficiently different to expedite recognition of the source of some of these difficulties. One substance of concern is the hydrogen cyanide normally found in COG acid gases. In the absence of some means of removing or decomposing this material before it enters the Claus Plant extensive corrosion within the unit is observed after a short period of time. This is due to the fact that, contrary to expectation, a substantial quantity of this material survives the burner flame. The various alternatives in its elimination are discussed. A second major contaminant in COG acid gases is particulate iron sulfide and iron cyanide. While the exact source of these materials is in doubt, there is little doubt that in the absence of their removal, inorganic blockages within the Claus Plant will occur. By properly accounting for the special properties of coke oven gas-derived acid gas we have recently achieved short term sulfur recovery efficiencies of 95% and higher.     

Road Dust Resuspension in the Vicinity of Limestone Quarries in Jordan

Abstract

Many areas in Jordan suffer from elevated levels of coarse particulate matter (PM₁₀). One potentially significant source of the observed PM is the resuspension of road dust in the vicinity of limestone quarries. To obtain data to assess the impact from this source, PM₁₀ road dust resus-pension factors near Abusiiah, a town to the north east of Amman surrounded by many quarries and brick factories, were measured. Measurements included PM₁₀ mass, particle size distributions, wind speed, and wind direction.The results showed that PM₁₀ concentrations could be as high as 600 µg/m³, and most of the airborne PM is in the coarse fraction. Loading trucks play a major role in resus-pending road dust, with an observed PM₁₀ emission rate of >6000 mg/km.     

Air Quality Measurements for the Aerosol Research and Inhalation Epidemiology Study

Abstract

Measurements of pollutant gases, airborne particulate matter mass and composition, and meteorology have been made at a core site near downtown Atlanta, GA, since August 1998 in support of the Aerosol Research and Inhalation Epidemiology Study (ARIES). This site is one of eight in the Southeastern Aerosol Research and Characterization network. The measurement objective is to provide a long-term, multivariate dataset suitable for investigating statistical associations of respiratory and cardiovascular disease with airborne particulate matter composition, meteorology, and copollutant gases through epidemiologic modeling. Measurements are expected to continue through 2010. Ancillary multiyear measurements at additional sites in the Atlanta metropolitan area and in short-term exposure assessments have been used to estimate the exposure/measurement error associated with using data from a central site to approximate human exposures for the entire area. To date, 13-, 25-, and 53-month air quality datasets have been used in epidemiologic analyses.     

The Southeastern Aerosol Research and Characterization Study,Part 3: Continuous Measurements of Fine Particulate Matter Mass and Composition

Abstract

Deployment of continuous analyzers in the Southeastern Aerosol Research and Characterization Study (SEARCH) network began in 1998 and continues today as new technologies are developed. Measurement of fine particulate matter (PM_2.5) mass is performed using a dried, 30 °C tapered element oscillating microbalance (TEOM). TEOM measurements are complemented by observations of light scattering by nephelometry. Measurements of major constituents include: (1) SO₄ ^2? via reduction to SO₂; (2) NH₄ ⁺ and NO₃ ^? via respective catalytic oxidation and reduction to NO, (3) black carbon (BC) by optical absorption, (4) total carbon by combustion to CO₂, and (5) organic carbon by difference between the latter two measurements. Several illustrative examples of continuous data from the SEARCH network are presented. A distinctive composite annual average diurnal pattern is observed for PM_2.5 mass, nitrate, and BC, likely indicating the influence of traffic-related emissions, growth, and break up of the boundary layer and formation of ammonium nitrate. Examination of PM_2.5 components indicates the need to better understand the continuous composition of the unmeasured “other” category, because it contributes a significant fraction to total mass during periods of high PM_2.5 loading. Selected episodes are presented to illustrate applications of SEARCH data. An SO₂ conversion rate of 0.2%/hr is derived from an observation of a plume from a coal-fired power plant during early spring, and the importance of local, rural sources of NH₃ to the formation of ammonium nitrate in particulate matter (PM) is demonstrated.