This report presents the geometric mean blood lead levels of an 80% cross-sectional sample of children aged 1-72 months in New Haven, Connecticut. Blood lead levels were related to age, sex and race. It was found that age and race were independently important sources of variation in blood lead levels. Sex of children in this age group was not related to differences in blood lead levels. The hig...

This paper describes simple modifications to thermally diffusive laminar flow ultrafine condensation particle counters (UCPCs) that allow detection of ∼1 nm condensation nuclei with much higher efficiencies than have been previously reported. These nondestructive modifications were applied to a commercial butanolbased UCPC (TSI 3025A) and to a diethylene glycol-based UCPC (UMN DEG-UCPC). Size a...

Abstract. Secondary organic aerosol (SOA), formed through oxidation of volatile compounds (VOCs), displays complex viscosity and phase behaviors influenced by temperature, relative humidity (RH), chemical composition. Here, the efficacy a multi-stage electrical low-pressure impactor (ELPI) for indirect water uptake measurements was studied ammonium sulfate (AS) aerosol, sucrose ?-pinene-derived...

Silica nanoparticles (SNPs) are widely used all around the world and it is necessary to evaluate appropriate risk management measures. An initial step in this process is to assess worker exposures in their current situation. The objective of this study was to compare concentrations and morphologic characteristics of fumed (FS) and sol-gel silica nanoparticles (SS) in two manufacturing facilitie...

Overexposure to welding fume constituents, particularly manganese, is of concern in the construction industry due to the prevalence of welding and the scarcity of engineering controls. The control effectiveness of a commercially available portable local exhaust ventilation (LEV) unit was assessed. It consisted of a portable vacuum and a small bell-shaped hood connected by a flexible 2 inch (50....

biological soil crusts (bscs) result from an intimate association between soil particles and cyanobacteria, algae, fungi, lichens and mosses in different proportions which live on the surface, or immediately in the uppermost millimeters of soil. therefore bscs cover the ground surface as a coherent layer, and influence primary processes such as carbon and nitrogen fixation and hydrologic status...

Impact pile driving is a multi-component problem which is associated to multi-directional ground vibrations. At first, vibration is transferred from the hammer to the pile and then to the common interface of pile and soil. This is then transferred to the environment and has great impact on the adjacent structures, causing disturbance to residents and also damage to the buildings. It is of high ...

BACKGROUND Camellia sinensis is the source of tea leaves and it is an economic crop now grown around the World. Tea seed oil has been used for cooking in China and other Asian countries for more than a thousand years. Tea is the most widely consumed beverages after water in the world. It is mainly produced in Asia, central Africa, and exported throughout the World. Some engineering properties (...

root morphological and distribution responses of signal grass (brachiaria decumbens) to long-term cattle grazing were examined in a tropical pasture in malaysia. the treatments were no grazing by cattle and grazing at a moderate stocking density (2.7 animal unit/ha) under rotational grazing for 33 years. the method consists of taking soil core using a soil corer to a depth of 30 cm and extracti...