Lead compounds Health effects

The metal is very effective as a sound absorber, is used as a radiation shield around X-ray equipment and nuclear reactors, and is used to absorb vibration. White lead, the basic carbonate, sublimed white lead, chrome yellow, and other lead compounds are used extensively in paints, although in recent years the use of lead in paints has been drastically curtailed to eliminate or reduce health hazards. 

ATSDR has not derived MRLs for lead. The EPA has not developed a reference concentration (RfC) for lead. EPA has also decided that it would be inappropriate to develop a reference dose (RfD) for inorganic lead (and lead compounds) because some of the health effects associated with exposure to lead occur at blood lead levels as low as to be essentially without a threshold (IRIS 1999). 

This review describes factors concerning the safety and environmental effects of organic germanium, tin and lead compounds. The factors involve the production and use of the elements, alkylation, degradation, toxicity, health effect assessment and so on. 

Modified from Harrison, R.M. and D.P.H. Laxen. 1981. Lead Pollution. Causes and Control. Chapman and Hall, NY. 168 pp. Demayo, A., M.C. Taylor, K.W. Taylor, and P.V. Hodson. 1982. Toxic effects of lead and lead compounds on human health, aquatic life, wildlife plants, and livestock. CRCCrit. Rev. Environ. Control 12 257-305. 

It should be noted that phenol is the simplest form, or parent compound, of the class of chemicals commonly referred to as phenols or phenolics, many of which are natural substances widely distributed throughout the environment. There is some confusion in the literature as to the use of the term phenol in some cases it has been used to refer to a particular phenolic compound that is more highly substituted than the parent compound (Doan et al. 1979), whereas in other cases it has been used to refer to the class of phenolic compounds (Beveridge 1997). This chapter, however, addresses only those health effects which can be directly attributable to the parent compound, monohydroxybenzene, or phenol. As Deichmann and Keplinger (1981) note It cannot be overemphasized that the structure-activity relationships of phenol and phenol derivatives vary widely, and that to accept the properties of individual phenolic compounds as being those of phenol is a misconception and leads to error and confusion. ... 

Lead is one of the most intensively studied hazardous compounds of the twentieth century. The more toxicologists and other researchers investigated the health effects of lead, the more they realized that even very low levels of lead exposure were hazardous. The most common biomarker of lead exposure is the blood lead level, usually measured in micrograms (jig) per one hundredth of a liter of blood (dl) or jlg/dl. For example, many regulatory agencies set 40 jlg/dl as a level of concern for adult male workers. Typically, at this level workers would be removed from the environment responsible for the exposure and ideally some determination would be made as to the cause of the exposure. The blood level of concern for children has dropped steadily, as shown in Figure 7.1. 

The interplay of HO, peroxy radicals, VOCs, and NO , species has substantial implications for tropospheric air quality. For instance, VOCs, NO , , and sunlight result in poor visibility from ozone and aerosol formation, together denoted as photochemical smog, which can lead to adverse health effects in sensitive individuals. Normally, we think of minimizing either class of compounds as beneficial to the atmosphere. However, minimizing VOC emissions only impacts ozone concentration in high-NO , areas. Moreover, in VOC-sensitive areas, reductions in NO , may lead to the overproduction of ozone. We can examine a simplified scheme for ozone production ... 

Not only is the acute toxicity of CR extremely low, with an estimated human LCt5Q over 100,000 mg mln/m, but the overt signs of exposure are even more transitory than those of CS. Eye Irritation passes In 15-30 min, and skin Irritation in 15-20 min. Erythema, which develops only on contaminated skin, passes In about an hour and does not lead to vesication or to contact sensitization. The abrupt Increase in blood pressure, which has been observed after whole-body drenches of CR In solution, subsides rapidly. Although available results show no long-term health effects of exposure to CR, there are no available data on the mutagenicity and carcinogenicity of this compound, and the data on teratology are limited. 

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