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R Ricks

Publications and source records attributed to R Ricks.

5 recordsLinked to original sources
PubMed1992

Field evaluation of a sampling and analytical method for environmental levels of airborne hexavalent chromium.

Hexavalent chromium, Cr(VI), has been classified as a human respiratory carcinogen. Airborne Cr(VI) emissions are associated with a number of industrial sources including metal plating, tanning, chromite ore processing, and spray painting operations; combustion sources such as automobiles and incinerators; and fugitive dusts from contaminated soil. There has been considerable interest within industry and the regulatory community to assess the potential cancer risks of workers exposed to Cr(VI) at levels substantially below the threshold limit value (TLV) of 50 micrograms/m3. To date, only the workplace sampling and analytical method (National Institute for Occupational Safety and Health [NIOSH] Method 7600) has been validated for measuring airborne Cr(VI), and it can accurately measure concentrations only as low as 500 ng/m3. This paper describes the field evaluation of a sampling and analytical method for the quantitation of airborne Cr(VI) at concentrations 5000 times lower than the current standard method (as low as 0.1 ng/m3). The collection method uses three 500-mL Greenberg-Smith impingers in series, operated at 15 Lpm for 24 hr. All three impingers are filled with 200 mL of a slightly alkaline (pH approximately 8) sodium bicarbonate buffer solution. The results of validation tests showed that both Cr(VI) and trivalent chromium, Cr(III), were stable in the collection medium and that samples may be stored for up to 100 days without appreciable loss of Cr(VI). Method precision based on the pooled coefficient of variation for replicate samples was 10.4%, and method accuracy based on the mean percent recovery of spiked samples was 94%. Both the precision and accuracy of the impinger method were within NIOSH criteria. This method could be used to measure ambient concentrations of Cr(VI) in the workplace caused by fugitive emissions from manufacturing processes or chromium-contaminated soils at workplace concentrations well below the current TLV (50 micrograms/m3) or permissible exposure limit (100 micrograms/m3).

Air Pollutants, Occupational↗
PubMed1986

Increased rate of cytomegalovirus infection among parents of children attending day-care centers.

We screened parents of children from three previously studied day-care centers where children have maintained high rates of cytomegalovirus (CMV) excretion, as well as parents of children not in day-care centers (controls), for antibody to CMV. Longitudinal serologic follow-up of seronegative parents revealed that 14 of 67 with children in the day-care centers acquired CMV, as compared with none of 31 controls (P less than 0.003). All 14 parents who seroconverted had a child who was shedding CMV in saliva or urine. Among the day-care group, acquisition of CMV occurred in 14 of 46 parents of children who shed CMV, as compared with none of 21 whose children did not excrete the virus (P less than 0.0001). There was no correlation between parental seroconversion and sex, race, age, number of years of education, marital status, occupation, or number of children in the home. CMV infection occurred in 9 of 20 parents (45 percent) with a child shedding CMV who was 18 months of age or less at enrollment. We conclude that children often transmit CMV to parents and could be an important source of maternal CMV infection during pregnancy.

Adult↗
PubMedDate not supplied

Epidemiology of cytomegalovirus infections in young children: day care vs. home care.

Infection rates with cytomegalovirus among children in three day care centers were compared to that found in a group of children cared for in the home who were from a similar socioeconomic background. Rates of viral excretion for Day Care Centers 1, 2 and 3 were 41% (28 of 68), 26% (15 of 58) and 55% (34 of 62), respectively, with a combined rate of infection for all children in day care of 41% (77 of 188). In contrast 15% (10 of 66) of children in home care were seropositive to cytomegalovirus, and only 2 of 25 (8%) were shedding virus (P less than 0.001). Although the median age of the group in home care was slightly lower, the two groups of children were similar in sex, race, breast-feeding and parental ages and educational background. The only other notable difference between the children in day care and those in home care was the environment in which they received care for almost 40 hours every week. Rates of infection varied also among the age groups within each center, with the highest rate within each center occurring in children 25 to 36 months old. Day care for young children is likely to be associated with high rates of infection with cytomegalovirus. The mechanisms of transmission that are responsible for these higher than expected rates of infection remain to be defined.

Age Factors↗
PubMedDate not supplied

Preparing to automate the case management process.

In this article, the authors discuss case management automation and the preparation that an organization should be making to install such a system successfully. They begin with a discussion of the goals of case management automation, and then review the steps that all facilities with case management programs can undertake to standardize their process, structure their organization, and strategically plan for case management automation. The current status of case management automation efforts also is discussed. The authors conclude by describing the efforts of one organization to develop an integrated case management documentation system.

Case Management↗