There. That's better.All traditional oil paint contains contaminants and solvents. Flake White / Foundation White / Cremnitz White contains Lead, which can kill or harm or kill you. Lemon Yellow must be treated in the same way. It contains Chrome and Barium; both real nasties that cause a lot of other problems, Cadmium paints are the most toxic. Cadmium is released in a form that is highly toxic.
Three methods of exposing your body to poisons are respiration, ingestion, and absorption (skin contact). Obviously, no one eats oil paint purposely. However, having oil paint on your hands can get into your digestive system if you do not take precautions to wash properly. Absorption (skin contact) is most prevalent in using oil paints. You can also inhale fumes of solvents used in oil paints.
Believe what you must. Oil paints can be and are toxic.Traditional oil paint does not contain "contaminants" whatever that may mean, or solvents. The only way a solvent could find its way into a tube of artist's oil colour is if the artist himself introduced it. As for lead white: Says Ralph Mayer in his, The Artist's Handbook of Materials and Techniques: "The use of flake white and other compounds which contain lead has been given considerable attention; most published discussions include warnings regarding their toxic effects. These materials may be handled with perfect safety if the hands and fingernails are well cleaned after using them, [. . .] White lead is poisonous only if swallowed or inhaled; on the whole its hazard has been somewhat exaggerated. Ordinarily the artist uses flake white only as an oil color. It should never be handled in dry powder form. [. . .] The toxicity of cadmium yellow, which has almost no significance to the painter, has been exaggerated, and the use of it should be governed by the same sensible precautions as in the handling of flake white."