Document zzG7D6JE73rYK5MnyoMD49Yeg

Cancer----------- zams. Continued from Page 6 recommending standards for occu pational exposure to a number of chemicals; and has published what it calls "criteria documents"'for more than 20 substances. The chemicals and substances include lead, asbestos, beryllium, trichloroethylene, toluene, ozone, several ketones and alkyl ben zenes, sulfur dioxide and ammo nia. Public hearings are to be held on all of these to develop stricter standards of exposure. In addition, the proposed stand ards . for lead, beryllium, trichloroethylene and toluene call for establishing what is called an "action level." That means that when workers are exposed to onehalf of the permissible level, em ployers would have to give medi cal examinations to check for possible effects of exposure. What seems to run through much of what is being learned about cancer-causing agents is the irony that ..technical advances often bring with them hidden haz ards. The convenience of the spray can for hair sprays, for example, depended oh the stability of the chemicals called fluorocarbons. Now many scientists believe that fluorocarbons are drifting up into the atmosphere and destroying the ,, protective layer of ozone, which screens out ultraviolet rays that can produce Ain cancer. The IARC study of suspect chemicals conveys the feeling that none is safe. In the past, for in- * stance, insecticides containing arsenic -- another substance on the list -- were used in the'vine- ' yards of Germany and Prance, exposing the laborers in the vine- ` yards to a cancer-causing chemi cal.