Specifically,health benefits from using PZT in ultrasonic medical imag-ing treatment and diagnosis far outweighs health hazard fromunlikely uncontrolled disposal of a medical device in the envi-ronment at the end-of-life. The message is clearly that as longas an adequate alternative is not available, replacement of lead-based piezoelectrics used in critical applications such thoselisted should not be forced (Table 1).