An American Association of State Highway Transportation Officials task force has recommended that heavy metals in glass beads for highway markings meet a maximum allowable limit of 200 ppm each for arsenic, lead, and antimony. The group — which has studied heavy metals in glass beads used on highway markings for the past four years — issued the recommendation to its materials committee, which voted unanimously to recommend that all member states adopt limits at least as stringent as these. www.transportation.org