Platinum uptake by horticultural crops

The chance for exposure of man to Pt has increased because of the loss of Pt by the catalytic converter used to reduce levels of harmful auto emissions. Whether Pt can be taken up by plants and introduced into man's primary food chain was studied. Pt uptake was analyzed by plasma emission spectroscopy from a week's exposure to 0.057, 0.57, or 5.7 ppm Pt inHoaglands solution. Roots and shoots of nine horticulturally important crops were tested. Chlorosis of young tissue was usually evidenced and dry weights of five species were significantly reduced by 5.7 ppm Pt. Several species showed increases in dry weight at the lowest concentration of Pt. All species accumulated Pt in significantly high amounts in the roots at all concentrations of Pt (for cauliflower and tomato > 1000 ppm at 5.7 ppm Pt). Only pepper, cauliflower, and radish accumulated Pt in their tops. Water loss was increased at low Pt treatment levels and decreased at high levels. The results indicate that Pt can enter into man's food chain directly and probably in large amounts from root crops.