Abstract: The invention relates to an environment-protective agent consisting of silicon-containing minerals for adsorbing radiactive metal isotopes and toxic heavy metals, which comprises as silicon-containing minerals with a particle size of 0.001 to 0.5 mm; a natural diatomaceous earth and at least two natural zeolite minerals of the general formulaM.sub.x O.Al.sub.2 O.sub.3.YSiO.sub.2.7H.sub.2 OwhereinM stands for sodium, potassium or calcium;x is a number between 1 and 2 inclusive of both extreme values;Y is 3 or 10; andZ is 6 or 7treated by dilute acid, washed to neutral, dried to a constant weight at a temperature up to 115.degree.0 C. and then heat-treated at 150.degree. to 350.degree. C., preferably at 250.degree. C., where the amount of each mineral ingredient independently of each other is at least 0.1% by weight up to 99.8% by weight calculated to the total weight of the agent.