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M J Schwar

Publications and source records attributed to M J Schwar.

4 recordsLinked to original sources
PubMed1988

Baseline metal-in-dust concentrations in Greater London.

Baseline concentrations of cadmium, copper, iron, lead and zinc have been measured in samples collected from surfaces remote from local sources of pollution across Greater London. The geometric means of concentrations of metals in dusts are 2.7 micrograms/g Cd, 79 micrograms/g Cu, 23,400 micrograms/g Fe, 370 micrograms/g Pb and 372 micrograms/g Zn. Concentrations of metals in dust have been shown to exhibit marked distributions across Greater London, and the survey has indicated the location of a number of areas of elevated metal-in-dust levels, for example the Lee Valley industrial area in north London, central London, and parts of east and west London. The concentrations found are compared with results reported in other studies, and the potential sources of metal contamination in the London area are discussed.

Cadmium↗
PubMed1988

Redecoration of external leaded paintwork and lead-in-dust concentrations in school playgrounds.

Playground lead-in-dust concentrations have been measured immediately after the external redecoration of 216 schools in 1983/4 and of 63 schools in 1984/5. Schools were divided into four age categories: A, pre-1914; B, 1914-1939; C, 1945-1965; and D, post-1965. The results show that concentrations can vary widely from school to school within a given age category. For each school, dust samples were collected from an area adjacent to the facade which had been redecorated, referred to here as the 'corridor' area, and from the 'remaining' playground area. The highest mean corridor concentrations were found in playgrounds of schools of age categories A and B, the highest mean value being 74,400 micrograms g-1. The highest value for age category D schools was 2600 micrograms g-1. The mean concentration for all schools in age categories A to D, was respectively 4720, 2820, 820 and 630 micrograms g-1 for the corridor area and 1180, 730, 400 and 440 micrograms g-1 for the remaining area. The highest lead-in-dust concentrations tended to occur within 2.5 m of the building facade. A limited number of measurements showed that concentrations in the corridor area tended to reduce with time, falling to half their initial value (after correcting for the local background level) in about 90-170 days. A model is suggested linking lead-in-dust concentrations in the corridor and remaining areas to lead-in-paint debris dust concentrations.

Child↗
PubMed1987

Dust deposition and the soiling of glossy surfaces.

Measurements of changes in reflectance caused by dust deposits on a glossy surface using a standard gloss-meter are described. A microscope slide exposed at a roadside and a rooftop site in central London was used as a convenient collector surface to simulate the soiling by dust of such glossy surfaces as glass, polished metal and plastic, automotive finishes and gloss paint. Measured reductions in gloss made over a number of weeks showed mean values between 1.4% and 1.9% per 6 h. Measurements made at the roadside showed an approximately linear relationship between gloss and percentage area of the slide covered by dust, as measured by a Magiscan II image analyser set up to measure particles greater than 5 microm in diameter. No such relationship was observed for measurements made at the rooftop site.

Journal Article↗