【明報專訊】THE authorities in mainland China, displaying a firm rejection of "foreign refuse", have tightened its policy on the import of recyclable materials. Punitive action has been taken on more than a thousand companies which have violated related regulations. This has set off a chain reaction, as some Hong Kong recyclers are now unable to export waste paper to the mainland. In response, they are ruminating a boycott, intending to stop accepting waste paper for a week.