HGW: Lead, Average total content (surface)

The mean is the median (synonym: 50. percentile, central value). It is the value above or below which 50% of all cases of a data group are located. The calculation is carried out on outlier-adjusted data collectives. The total content is determined from the aqua regia extract (according to DIN ISO 11466 (1997)). The concentration is given in mg/kg. The salary classes take into account, among other things, the pension values of the BBodSchV (1999). These are 40 mg/kg for sand, 70 mg/kg for clay, silt and very silty sand and 100 mg/kg for clay. According to LABO (2003) a sample count of >=20 is required for the calculation of background values. However, the map also shows groups with a sample count >= 10. This information is then only informal and not representative.