(April-May 1985). The children and their parents were informed in advance about the nature, purpose, and date of the test. At the same time written parental consent was requested and a questionnaire seeking details of general health and with special reference to asthma and any other past or recent chest illness was completed. Roughly one week before the test the height of most of the children was measured by JNT at school using a Microtoise tape.8 On the day of the test the children were taken, one class at a time, by bus to a hospital gymnasium where the ambient temperature was 16-20'C and the relative humidity was 37-44%.9 The children were instructed not to

A cheap telemetric device, the 'Sporttester', has been shown to be useful in monitoring the free running test for bronchoconstriction. The free running test is one of the most potent bronchoconstrictive stimulants in subjects with bronchial hyperreactivity.1 The test consists of

occupational hygienist (field consultant group, Health and Safety Executive, Edinburgh), showed levels ofmercury in the air to be between three to eight times the recommended limit. Advice was given about improving working practices in the three premises where raised concentrations of mercury in urine were found and in one where inadequate protection was provided, although no work had been done on sphygmomanometers for almost two months.