Document 44LKDg1xeZ8d9z5y8Qvp1OoKV

ELEMENTS OF INDUSTRIAL TOXICOLOGY hculady if applied often or in large quan The metal is essentially harmless. Al tities though it can be vaporized at high tempera Continued absorption of iodine has an ef fect on the mucous membranes distinct from its local action on the skin It produces ir tures, such temperatures are not usually at tained m casting, soldering, or heat treating baths ritation and inflammation of skm and mu Casting and soldering pots should have cous membrane tissue and seems to escite local exhaust hoods to get nd of lead vapor minor infection into renewed activity or lead compounds which may be earned off See Industrial Data Sheet 457. with volatile fluxes It is at least equally important that the surface of the lead be Iron oxide fume was observed some years ago to cause a mottling m the lung X-rays of welders similar to that of i1kvkis The most important differences between the ef fects of iron oxide and silica are that the kept free Horn dross and that the dross container be enclosed under the same hood so that dross can be removed from the pot and the container covered and removed, all under exhaust. presence of iron pigmentation or siderosis Likewise, on large soldering jobs the does not increase the tendency of die lung soldering operation should be locally ex to develop tuberculosis and the welders with hausted, primarily to prevent nose and this condition do not seem to have any dis throat untabon from acid fluxes More ability as a result of it It occurs in hema importantly, the furnaces used for heating tite miners and in welders who work in con tile soldering irons should be exhausted be fined spaces without enough ventilation. cause m these furnaces considerable lead is Most authorities feel that the concentra mvariably oxidized. tion of iron m the air should be kept below Assembly of battery plates and burning the point at which it collects in the lung See Hygienic Guide. on of the connectors should be done on gnlle-top tables with down-draft ventila tion This installation pins regular air sam Lead was one of the first industrial ma terials to be recognized as a serious health hazard, and it still accounts for more cases of disability than any other angle air con taminant In industrial work, lead enters the system mainly m the form of dust by inhalation. Lead compounds can produce poisoning when they are swallowed, but absorption from die digestive system is slow and in efficient, so that large doses of most lead compounds are required and poisoning de velops slowly In the respiratory system, on the other hand, most lead compounds are absorbed rapidly and completely so that poi soning will develop from much lower doses It is not even necessary that the compound penetrate deeply into the respiratory sys tem. It has been demonstrated experimen tally that lead compounds are absorbed rapidly and completely from the nasal pas sages when they have no chance to go either into the digestive system or deeper mto pling to ensure control of contamination and physical examinations to keep track of lead absorption by employees, can eliminate lead poisoning from battery plants The poisoning produced by inhalation of solid inorganic lead compounds commonly causes symptoms of lead colic and lead anemia. Stipple cells or other readily stained cells in the circulating blood are good indi cators of lead absorption, although not so good as the direct measurement of lead con tent of the blood or unne. Urinalyses for lead can now be run routinely and cheaply and with sufficient accuracy by polarographic or spectrographic methods Lead tetraethyl and other lead alkyls are likely to be much more rapidly progressive as poisons than the nonvolatile compounds and are much more likely to attack the nervous system than to produce gastroin testinal symptoms. These effects are prob ably typical of the volatile lead compounds, none of which is common m industry the respiratory system. See Industrial Data Sheet 443 and Hy Prevention of lead poisoning is almost gienic Guide. entirely a matter of good housekeeping and dust control. To prevent ingestion food or Lethanes--see Thiocyanates (aliphatic). dnnks should not be taken mto workrooms where lead compounds are handled Lindane--see Hexnchlorucyclohexane. 40-38