HONG KONG'S safety record on construction sites is appalling, a High Court judge said yesterday when awarding damages to the family of a man killed when he fell 19 floors down an unguarded lift shaft. Mr Justice Kaplan said one in three employees on construction sites were injured at work, and last year about 100 workers were killed. He also said that injuries at work sites connected with the new airport were at an unacceptable level. ''This appalling statistic can only be reversed if all concerned with construction sites make a real and determined effort to guard against the obvious risks connected with the sites,'' he said. He said lift shafts were dangerous and should be properly boarded. The wood should not break, as it did in this case under the weight of a workman. Before boarding, the area should be roped off, with oral and written warnings, and safety supervisors should be on site more often. He awarded compensation totalling $768,000 to the widow and daughter of Lau Chuen-fat, 45, who died on June 15, 1989, when working on a site in Wang Lung Street, Tsuen Wan. Damages were to be paid by the main contractor, Shun Shing Engineering Company, and Chang Chun-ying, a sub-contractor, at a ratio of 70 per cent and 30 per cent. Mr Justice Kaplan said Mr Chang had refreshments for the workers placed on planks partially covering the lift shaft. The deceased fell when he went to collect them. This arrangement was an almost certain recipe for disaster. Mr Chang failed to appear at the hearing. The judge said the main contractor admitted that the lift shaft was not properly boarded and the safety supervisor agreed it was dangerous. The judge said the lift shafts were in a disgraceful state. ''Unboarded lift shafts are well-known to be death traps. Many cases come before these courts involving injuries or death caused by persons falling down lift shafts.''