translate English to French: SUBSTANCE-SPECIFIC CHANGES  2.1 Thallium 2.2 Polychlorinated Biphenyls 2.3 Dioxins, Furans, and Hexachlorobenzene 2.4 N-Nitrosodimethylamine  3.
CHANGEMENTS CONCERNANT CERTAINES SUBSTANCES  2.1 Thallium 2.2 Biphényles polychlorés 2.3 Dioxines, furannes et hexachlorobenzène 2.4 N-nitrosodiméthylamine  3.