The purposes of this study were a) to summarize measurements of airborne (respirable) crystalline silica dust exposure levels among U.S. workers, b) to provide an update of the 1990 Stewart and Rice report on airborne silica exposure levels in high-risk industries and occupations with data for the time period 1988-2003, c) to estimate the number of workers potentially exposed to silica in indus...

Objectives It has been known for centuries that crystalline silica induces silicosis. However, there are different entities of crystalline silica. Siliceous earth is a worldwide unique blend of amorphous and cryptocrystalline silica and lamellar kaolinite. This retrospective cohort study is the first that investigated the silicosis risk of siliceous earth. Methods The cohort consists of employe...

Abduelmula R Abduelkarem is Associate Professor of Clinical Pharmacy and Pharmacy Practice, Department of Clinical Pharmacy and Pharmacy Practice, College of Pharmacy and Health Sciences, Ajman University of Science and Technology Network, Ajman, United Arab Emirates; Hawa J El-Shareif is Adult Endocrinologist, Endocrine Department, Tripoli Medical Centre (Tripoli University, Faculty of Medicin...

OBJECTIVE Isolation of potentially pathogenic bacteria from carpets in hospitals has been reported earlier, but not from carpets in mosques. The aim of the present study is to determine the pathogenic and potentially pathogenic bacteria that may exist on the carpets of mosques in Tripoli, Libya. METHODS Dust samples from carpets were collected from 57 mosques in Tripoli. Samples were examined...

The fabrication of nanoporous poly(vinylidene fluoride) (PVDF) and PVDF/nickel nanocomposites from semicrystalline block copolymer precursors is reported. Polystyrene-block-poly(vinylidene fluoride)-block-polystyrene (PS-b-PVDF-b-PS) is prepared through functional benzoyl peroxide initiated polymerization of VDF, followed by atom transfer radical polymerization (ATRP) of styrene. The crystalliz...

Membrane-based gas separation processes can address key challenges in energy and environment, but for many applications the permeance and selectivity of bulk membranes is insufficient for economical use. Theory and experiment indicate that permeance and selectivity can be increased by using two-dimensional materials with subnanometer pores as membranes. Motivated by experiments showing selectiv...

In this paper, we bring forward an effective strategy, solvothermal postsynthesis, to prepare ordered mesoporous silica materials with highly branched channels. Structural characterizations indicate that the titled mesoporous materials basically have the cubic double gyroidal (space group Ia-3d) structure with small fraction of distortions. The mesopore sizes and surface areas can be up to 8.8 ...

Construction dust is one of the most concerned pollutants presenting risks to human health. Dust from construction activities, particularly true for silica dust, have an adverse effect on the local environment and on the health of local residents, as well as on those working on the site. There is a long-term concern about the over exposure of construction workers to respirable crystalline silic...

High-pressure (0.8 gigapascals) granulite facies garnet from Gore Mountain, New York, hosts multiple solid inclusions containing the low-pressure silica polymorph cristobalite along with albite and minor ilmenite. Identification of cristobalite is based on Raman spectra, electron microprobe analysis, and microthermometric measurements on the alpha/beta phase transformation. The cristobalite plu...