Yip's assurance that all solder baths have localized exhausts is not true. For instance, the solder baths and acid baths used in the tin plating process at Semiconductor Devices in Aberdeen have no localized exhausts. That is neither adequate nor particularly unusual. The point is that not all soldering work involves solder baths. None of these workers is adequately protected.
Solders contain tin, lead, antimony, arsenic, cadmium, silver and zinc.
Exposure to the oxidized fumes of these metals can cause anaemia, digestive problems, nerve damage, lung problems, heart trouble, reproductive problems and increased cancer risks. Fumes from fluxes cause a range of ailments affecting the skin, eyes, nose and throat, chest, stomach, kidneys, liver, nervous system, heart and reproductive system, and increase cancer risks. Similarly serious problems are associated with chemicals found in the epoxy resins, hardeners and solvents used to make printed circuit boards. There are other problems, not associated with chemicals. Testing for vision and hearing impairment is simple, and both the Kwuntong group and the union did this in their studies, but determining the effects of chemical exposure is more difficult, often entailing complicated laboratory analysis of blood samples and tests which cannot be done in Hong Kong.