Lead in drinking water

An important source of lead leading to human exposure is that contained in drinking water. Treatment processes for public water supplies are unlikely to reduce the concentration of filterable lead in the raw water, except where processes such as precipitation water softening are used [25]. Fortunately, however, the concentrations of lead in the raw water are generally fairly low, 0.01 mg dm . Many tap water samples, nevertheless, reveal significantly elevated lead levels, which may occasionally rise to over 1 mg dm . These elevated concentrations are found in areas where the plumbing system is based on lead pipes. 

The highest lead concentrations occur in standing water first drawn from the tap. They then generally decline after a few litres of water have been drawn off. The measured concentrations of lead in tap water must be viewed in the light of the national and international standards, which have been variously set at 0.05 or 0.1 mg dm [25]. The preliminary results of a recent survey of tap water in England, Wales and Scotland suggest that 1.7 million households ca. 9.2%) have a first draw lead concentration in excess of even the higher standard. This number falls to 0.8 million households ca. 4.4%) when daytime samples are considered [25]. 

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Suppose you are asked to develop a way to determine the concentration of lead in drinking water. How would you approach this problem To answer this question it helps to distinguish among four levels of analytical methodology techniques, methods, procedures, and protocols. ... 

Seminar Lead in Drinking Water , Lorch Foundation, Lane End, High Wycombe, Organised by the Water Research Centre, (March 1981)... 

G.24 The concentration of toxic chemicals in the environment is often measured in parts per million (ppm) or even parts per billion (ppb). A solution in which the concentration of the solute is. 1 ppb by mass has. 3 g of the solute for every billion grams (1000 t) of the solution. The World Health Organization has set the acceptable standard for lead in drinking water at... 

EPA regulations also limit lead in drinking water to 0.015 milligrams per liter (mg/L). The 1988 Lead Contamination Control Act requires the Consumer Product Safety Commission (CPSC), EPA, and the states to recall or repair water coolers containing lead. This law also requires new coolers to be lead-free. In addition, drinking water in schools must be tested for lead, and the sources of lead in this water must be removed. 

Decreases in sperm motility and increased acid phosphatase activity were reported to result from oral administration of 0.05 mg/kg lead in drinking water to male rats for 20-30 days in a study from the former U.S.S.R. (Krasovskii et al. 1979). Dystrophic changes of the Leydig cells were reported in gonadal tissues of rats exposed to doses as low as 0.005 mg lead/kg/day. The weaknesses of the study include absence of data on the strain and number of rats used, and the fact that PbB levels were not reported. 

EPA. 1979a. The environmental lead problem An assessment of lead in drinking water from a multimedia perspective. Washington, DC U.S. Environmental Protection Agency. EPA 570/9-79-003, NTIS PB-296556. 

Regulating the presence of lead in drinking water systems. 

Following a recent World Health Organization (WHO) recommendation to lower the permissible level of lead in drinking water from 50 pgl to 10 pgl, methodologies were required to detect a tenth of the new Hmit, i.e. 1 pgl Work was carried out at STL to introduce ICP-MS the Hmit of detection (LOD) is much lower by this technique than by furnace. Good results for Cd, Cr, Cu, Pb, Ni, Zn and Ag have been achieved by ICP-MS using the following three internal standards Sc (45), In (115) and Ir (193). This... 

Drill, S. Konz, J.H. Mahar Morse, M. The Environmental Lead Problem An Assessment of Lead in Drinking Water from a Multi-Media Perspective, U.S. Environmental Protection Agency, Criteria and Standards Division, PB-296 566, May 1979. 

The action level for lead in drinking water is 15 rg/L. Its content in food and house paints is regulated in the USA by the Food and Drug Administration. 

A. P. Lindomar, H. S. Ferreira, W. N. L. Dos-Santos and S. L. C. Fereira, Simultaneuous pre-concentration procedure for the determination of cadmium and lead in drinking water employing sequential multielement flame atomic absorption spectrometry, Microchem. J., 87(1), 2007, 77-80. 

It is uncertain just how relevant the results for these resin studies are to actual drinking waters because lead in drinking water is likely to be in solution and to have had time to reach equilibrium. Tests on actual drinking waters with background levels of lead will provide more definite answers to these questions. 

E m Mi i ti A concentration of 1 ppm for a substance means that each kilogram of solution contains 1 mg of the solute. For dilute aqueous solutions near room temperature, where 1 kg has a volume of 1 L, 1 ppm also means that each liter of solution contains 1 mg of solute. In the same way, a concentration of 1 ppb means that each liter of an aqueous solution contains 0.001 mg of solute. Values in ppm and ppb are frequently used for expressing the concentrations of trace amounts of impurities in air or water. Thus, you might express the maximum allowable concentration of lead in drinking water as 50 ppb, or about 1 g per 20,000 L. 

Harrison, R.M. and Laxen, D.P.H., 1980. Physicochemical speciation of lead in drinking water. Nature, 286 791-793. 

Environmental Protection Agency. 2006. Lead in drinking water. Available at http //www.epa.gov/ safewater/lead/b asicinformation.html. 

When making some analytical measurements of a quantity (x), for example the concentration of lead in drinking water, all the results obtained will contain some... 

The amount of lead in drinking water frequently diminishes on standing, probably in consequence of precipitation as lead carbonate.3... 

Lead in Drinking Water. The naturally soft, slightly acidic, plumbosolvent water of the Loch Katrine water supply for the Glasgow area was recognized many years ago to release lead from the lead pipes and tanks in the domestic plumbing of the Victorian and subsequent (even post-World War II) eras. ... 

Since 1989, as regulatory upper limits for lead in drinking water have fallen, e.g. to 50 pg (EC) and now to 10 pg (WHO), orthophosphate has been added to the water supply in Glasgow to precipitate insoluble lead compounds such as Pb3(P04)2 and Pb5(P04)30H. This has resulted in a fall in the proportion of households with water lead > 10 pg from 49% in 1981 to 17% in 1993. Despite this improvement, an estimated 13% of infants were still exposed via bottle feeds to tap water lead concentrations in excess of 10 pg and it seems very unlikely that further treatment of the water supply will be able to guarantee water lead concentrations <10 pg L . ... 

Concentrations can be expressed in many forms. One unit of concentration used in pollution measurements that involve very low concentrations is parts per million, or ppm. Parts per million is the number of grams of solute in 1 million grams of solution. For example, the concentration of lead in drinking water may be given in parts per million. 

Ryan, P. B., Huet, N., and Macintosh, D. L., 2000, Longitudinal investigation of exposure to arsenic, cadmium, and lead in drinking water Environmental Health Perspectives, v. 108, no. 8, p. 731-735. 

The maximum concentration of lead in drinking water recommended by the World Health Organization is 0.5 mg 1 Comprehensive results on lead in the environment are presented elsewhere [9]. 

In the Slovak Republic in 1996 the median concentration of lead in drinking water was 2.6 p.g/1. None of the 235 samples exceeded the limit value for lead (Food Research Institute, 1997). In 1998 the national limit value for lead concentration in drinking water was lowered from 50 to 10 p.g/1 (Anon, 1998). 

Regarding lead in drinking water, the Hungarian National Environmental Health... 

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