Indoor air quality at the Correr Museum, Venice, Italy.

Two multidisciplinary field surveys, one in winter and the other in summer have monitored the indoor microclimate, air pollution, deposition and origin of the suspended particulate matter and microorganisms of the Correr Museum, Venice. In addition, this study was focused to identify the problems caused by the heating and air conditioning system (HAC) and the effects due to the presence of carpets. Heating and air conditioning systems (HACs), when chiefly designed for human welfare, are not suitable for conservation and can cause dangerous temperature and humidity fluctuations. Improvements at the Correr Museum have been achieved with the assistance of environmental monitoring. The carpet has a negative influence as it retains particles and bacteria which are resuspended each time people walk on it. The indoor/outdoor pollutants ratio is greater in the summertime, when doors and windows are more frequently open to allow for better ventilation, illustrating that this ratio is mainly governed by the free exchange of the air masses. The chemical composition, size and origin of the suspended particulate matter have been identified, as well as the bacteria potentially dangerous to the paintings. Some general suggestions for improving indoor air quality are reported in the conclusions.

Plastic wrapping of cot mattresses: results from a pilot study.

AIM: To assess the prevalence of plastic wrapping of cot mattresses and their thickness. METHODS: Mothers of infants less than six months attending Plunket clinics in Central Auckland were interviewed. The thickness of the plastic was measured. RESULTS: 99 of 110 (90%) mothers invited to participate were visited at home. The sample was socioeconomically advantaged. Most infants were breastfed and few slept prone. The prevalence of plastic wrapped cot mattresses was 23.2%, of which sixteen (out of 23) used BabeSafe and seven used other types. The mean thickness of the BabeSafe was 0.15 mm (range 0.12-0.19 mm) and the other types were 0.10 mm (range 0.04-0.13 mm). One sample of plastic was 0.04 mm. CONCLUSION: Thin plastic wrapping is being used and is potentially dangerous.

Ground level nitrogen dioxide concentrations in the rural Waikato Valley, New Zealand.

Ground level nitrogen dioxide (NO2) concentrations have been measured for one year over an area of 400 square kilometres in rural New Zealand using an array of 21 sites. Three passive samplers were exposed at each site for intervals of two weeks from August 1989 to August 1990. The exposure sites were centred around the Waikato Valley township of Huntly (population 6900). Important features of the survey area include a 1000 MW thermal power station situated on the outskirts of the town, the Waikato River and State Highway 1, a major north-south traffic route along the valley. The NO2 concentrations in the survey area ranged from below 0.1 to 10.1 ppb, with an annual average of 1.2 ppb. Seasonal variations indicate summer values about three times lower than those found in the winter. The spatial distribution of NO2 appears to be related to contributions from State Highway 1.

A passive sampler for hydrogen sulfide.

The silver nitrate/fluorescein mercuric acetate fluorimetric method for the measurement of atmospheric hydrogen sulfide has been adapted to passive sampling. Standard samplers have been tested and used in both indoor and outdoor environments. Sampler performance was not dependent on construction materials or sunlight intensity and gave similar results to active sampling. Two case studies were carried out, one in the Horniman Museum and its associated storage and study building, London, UK, and the other in the vicinity of a pulp and paper mill and geothermal area North Island, New Zealand. The detection limit of the samplers (50 ppt average for a one-week exposure) provides the opportunity to make measurements in a variety of locations provided exposure times are sufficiently long, i.e., up to one month in areas of low hydrogen sulfide concentration.