Ken, that's not true. Lead presents two major hazards to hobbyists:
1. Handling. Lead surfaces have a very fine, almost microscopic dust. Any time you're handling lead, you should wear latex gloves and wash your hands and face well after you're done. Ths includes things like lead shot and lead fishing sinkers as well as lead weights in locomotives.
2. Shaping or grinding lead. Anything that disturbs the lead surface will generate a considerable amount of lead dust. Without having an industrial quality respirator, you should never shape or grind lead. You are increasing your risk of inhaling lead dust many fold by such activities. Inhalation of lead dust is the chief cause of cancer, not ingestion.
You should also never smoke, eat, or drink while handing or working with lead products. There are alternatives to lead that are much safer for model railroad use. Why exposure yourself to a known, potent carcinogen if you don't have to?