translate English to French: It has also been suggested that contaminant levels may be reaching a new steady state at levels lower than those of the 1970s but higher than background levels.
On s'attend Ã©galement Ã ce que les concentrations de contaminants atteignent un nouvel Ã©quilibre Ã des valeurs infÃ©rieures Ã celles des annÃ©es 1970, mais supÃ©rieures Ã celles des concentrations de fond.