WELLINGTON -- New Zealand's Occupational Safety and Health Service (OSH) has warned workers in some industries that not going to the toilet regularly could be a cause of bladder cancer, DPA reported.

A study of 123 cases begun in January 2001 found that 33 of them, or 27 per cent, had worked in occupations known to cause bladder cancer and that truck drivers were particularly at risk.

OSH doctor Evan Dryson said: "There is good research evidence linking truck (and other vehicle) driving with bladder cancer." "There appears to be higher risks associated with exposure to diesel fumes, but non-diesel truck drivers are also at risk, due to traffic fumes in general." "It has also been postulated that insufficiently frequent emptying of the bladder may predispose to cancer of the bladder." As a result of the study, OSH issued a warning, recommending that vehicle drivers, especially those going long distances, should "not unduly prolong bladder emptying periods" and make sure their engines are well maintained with no fume leaks into the cab.

Dryson said overseas data estimated that 8 per cent of all cancers were due to occupational causes, but this rose to 25 per cent for bladder cancer.

He said the New Zealand research showed that engineering and metal workers as well as drivers had developed bladder cancer likely to have been caused by their jobs.

He blamed exposure to cutting and lubricating oils and fluids, and specifically inhalation of fine oil mists.

OSH recommended equipment should be shielded to avoid oil mist escaping and workers should wear visors or respirators.

Other jobs at risk included farmers, orchardists and horticulturalists (from exposure to pesticides and insecticides) and painters, textile workers and hairdressers (solvents and dyes).

OSH said research had shown a link to telephonists and retail workers, particularly if they had been on the job for 10 years, but the cause was not immediately apparent.

"It has been postulated that second-hand cigarette smoke, environmental pollutants and insufficiently frequent emptying of the bladder (due to the 'trapped' nature of the job) may be factors in causation," Dryson said.