Magnetic fields from domestic appliances in the UK

In a survey of 50 UK homes the 50 Hz fundamental and harmonic magnetic fields generated by 806 domestic appliances found in the homes, and used regularly by mothers, were measured. Measurements were made in the direction of most likely access, and from the surface of the appliances. Mothers completed a questionnaire on the use of appliances and were monitored for 24 h so that acquired exposure could be compared with the measured ambient fields in the home. Appliances were measured at standard distances and an algorithm was used to calculate fields at 100 and 50 cm to remove room background contributions. A few appliances generated fields in excess of 0.2 mu T at 1 m: microwave cookers 0.37 +/- 0.14 mu T; washing machines 0.27 +/- 0.14 mu T; dishwashers 0.23 +/- 0.13 mu T; some electric showers 0.11 +/- 0.25 mu T and can openers 0.20 +/- 0.21 mu T. Of continuously operating devices, only central heating pumps (0.51 +/- 0.47 mu T), central heating boilers (0.27 +/- 0.26 mu T) and fish-tank air pumps (0.32 +/- 0.09 mu T) produced significant fields at 0.5 m. There were no obvious ways to group different types of appliances as high- or low-strength sources. Mothers spent on average about 4.5 h per day in the kitchen, where the strongest sources of magnetic field were located.