<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><a href="http://en.wikipedia.org/wiki/Lead">http://en.wikipedia.org/wiki/Lead</a> ( the following are excepts from the site .... )</div><div><br></div><div><span class="Apple-style-span" style="font-size: 17px; font-family: -webkit-sans-serif; line-height: 25px; "><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><b>Lead</b> (pronounced <span title="Pronunciation in the International Phonetic Alphabet (IPA)" class="IPA" style="font-family: inherit; "><a href="http://en.wikipedia.org/wiki/Wikipedia:IPA_for_English" title="Wikipedia:IPA for English" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">/ˈlɛd/</a></span>) is a main-group <a href="http://en.wikipedia.org/wiki/Chemical_element" title="Chemical element" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">element</a> with symbol <b>Pb</b> (<a href="http://en.wikipedia.org/wiki/Latin_language" title="Latin language" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">Latin</a>: <span lang="la" xml:lang="la"><i>plumbum</i></span>) and <a href="http://en.wikipedia.org/wiki/Atomic_number" title="Atomic number" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">atomic number</a> 82. Lead is a soft, <a href="http://en.wikipedia.org/wiki/Malleable" title="Malleable" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">malleable</a> <a href="http://en.wikipedia.org/wiki/Poor_metal" title="Poor metal" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">poor metal</a>, also considered to be one of the <a href="http://en.wikipedia.org/wiki/Heavy_metal_(chemistry)" title="Heavy metal (chemistry)" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">heavy metals</a>. Lead has a bluish-white color when freshly cut, but tarnishes to a dull grayish color when exposed to air. It has a shiny chrome-silver luster when melted into a liquid.</div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; ">Lead is used in building construction, <a href="http://en.wikipedia.org/wiki/Lead-acid_battery" title="Lead-acid battery" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">lead-acid batteries</a>, <a href="http://en.wikipedia.org/wiki/Bullet" title="Bullet" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">bullets</a> and <a href="http://en.wikipedia.org/wiki/Lead_shot" title="Lead shot" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">shot</a>, weights, and is part of <a href="http://en.wikipedia.org/wiki/Solder" title="Solder" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">solder</a>,<a href="http://en.wikipedia.org/wiki/Pewter" title="Pewter" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">pewter</a>, <a href="http://en.wikipedia.org/wiki/Fusible" title="Fusible" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">fusible</a> <a href="http://en.wikipedia.org/wiki/Alloy" title="Alloy" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">alloys</a> and <a href="http://en.wikipedia.org/wiki/Radiation_shield" title="Radiation shield" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">radiation shields</a>. Lead has the highest <a href="http://en.wikipedia.org/wiki/Atomic_number" title="Atomic number" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">atomic number</a> of all <a href="http://en.wikipedia.org/wiki/Stable_element" title="Stable element" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">stable elements</a>, although the next element, <a href="http://en.wikipedia.org/wiki/Bismuth" title="Bismuth" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">bismuth</a>, has a <a href="http://en.wikipedia.org/wiki/Half-life" title="Half-life" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">half-life</a> so long (longer than the estimated age of the universe) it can be considered stable. Like <a href="http://en.wikipedia.org/wiki/Mercury_(element)" title="Mercury (element)" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">mercury</a>, another <a href="http://en.wikipedia.org/wiki/Heavy_metal_(chemistry)" title="Heavy metal (chemistry)" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">heavy metal</a>, lead is a potent <a href="http://en.wikipedia.org/wiki/Neurotoxin" title="Neurotoxin" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">neurotoxin</a> that accumulates in soft tissues and bone over time. <a href="http://en.wikipedia.org/wiki/Lead_poisoning" title="Lead poisoning" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">Lead poisoning</a> was documented in ancient Rome, Greece, and China.</div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><br></div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><span class="Apple-style-span" style="font-size: 26px; ">Health effects</span></div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><div class="rellink noprint relarticle mainarticle" style="font-style: italic; padding-left: 2em; ">Main article: <a href="http://en.wikipedia.org/wiki/Lead_poisoning" title="Lead poisoning" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">Lead poisoning</a></div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; ">Lead is a poisonous metal that can damage nervous connections (especially in young children) and cause blood and brain disorders. Because of its low reactivity and solubility, lead poisoning usually only occurs in cases when the lead is dispersed, like when sanding lead based paint, or long term exposure in the case of<a href="http://en.wikipedia.org/wiki/Pewter" title="Pewter" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">pewter</a> tableware. Long term exposure to lead or its salts (especially soluble salts or the strong oxidant PbO<sub style="line-height: 1em; ">2</sub>) can cause <a href="http://en.wikipedia.org/wiki/Nephropathy" title="Nephropathy" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">nephropathy</a>, and <a href="http://en.wikipedia.org/wiki/Colic" title="Colic" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">colic</a>-like abdominal pains. The effects of lead are the same whether it enters the body through breathing or swallowing. Lead can affect almost every organ and system in your body. The main target for lead toxicity is the nervous system, both in adults and children. Long-term exposure of adults can result in decreased performance in some tests that measure functions of the nervous system. It may also cause weakness in fingers, wrists, or ankles. Lead exposure also causes small increases in blood pressure, particularly in middle-aged and older people and can cause anemia. Exposure to high lead levels can severely damage the brain and kidneys in adults or children and ultimately cause death. In pregnant women, high levels of exposure to lead may cause miscarriage. Highlevel exposure in men can damage the organs responsible for sperm production.</div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; ">The concern about lead's role in cognitive deficits in children has brought about widespread reduction in its use (lead exposure has been linked to <a href="http://en.wikipedia.org/wiki/Learning_disabilities" title="Learning disabilities" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">learning disabilities</a><sup id="cite_ref-9" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-9" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>10<span>]</span></a></sup>). Most cases of adult elevated blood lead levels are workplace-related.<sup id="cite_ref-10" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-10" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>11<span>]</span></a></sup> High blood levels are associated with delayed puberty in girls.<sup id="cite_ref-11" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-11" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>12<span>]</span></a></sup> Lead has been shown many times to permanently reduce the cognitive capacity of children at extremely low levels of exposure.<sup id="cite_ref-12" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-12" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>13<span>]</span></a></sup> There appears to be no detectable lower limit, below which lead has no effect on cognition.</div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; ">In the 20th century, the use of lead in paint <a href="http://en.wikipedia.org/wiki/Pigment" title="Pigment" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">pigments</a> was sharply reduced because of the danger of lead poisoning, especially to children.<sup id="cite_ref-13" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-13" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>14<span>]</span></a></sup><sup id="cite_ref-14" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-14" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>15<span>]</span></a></sup><sup id="cite_ref-15" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-15" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>16<span>]</span></a></sup> By the mid-1980s, a significant shift in lead end-use patterns had taken place. Much of this shift was a result of the U.S. lead consumers' compliance with environmental regulations that significantly reduced or eliminated the use of lead in non-battery products, including <a href="http://en.wikipedia.org/wiki/Gasoline" title="Gasoline" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">gasoline</a>, paints, solders, and water systems. Lead use is being further curtailed by the European Union's <a href="http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive" title="Restriction of Hazardous Substances Directive" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">RoHS directive</a>. Lead may still be found in harmful quantities in stoneware, vinyl (such as that used for tubing and the insulation of electrical cords), and brass manufactured in China. Between 2006 and 2007 many children's toys made in China were recalled, primarily due to lead in paint used to color the product.</div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; ">Older houses may still contain substantial amounts of <a href="http://en.wikipedia.org/wiki/Lead_paint" title="Lead paint" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">lead paint</a>. White lead paint has been withdrawn from sale in industrialized countries, but the yellow <a href="http://en.wikipedia.org/wiki/Lead_chromate" title="Lead chromate" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">lead chromate</a> is still in use; for example, <a href="http://en.wikipedia.org/w/index.php?title=Holland_Colours&action=edit&redlink=1" class="new" title="Holland Colours (page does not exist)" style="text-decoration: none; color: rgb(204, 34, 0); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">Holland Colours</a> Holcolan Yellow. Old paint should not be stripped by sanding, as this produces inhalable dust.</div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; ">Lead salts used in pottery glazes have on occasion caused poisoning, when acidic drinks, such as fruit juices, have leached lead ions out of the glaze.<sup id="cite_ref-16" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-16" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>17<span>]</span></a></sup> It has been suggested that what was known as "<a href="http://en.wikipedia.org/wiki/Devon_colic" title="Devon colic" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">Devon colic</a>" arose from the use of lead-lined presses to extract apple juice in the manufacture of <a href="http://en.wikipedia.org/wiki/Cider" title="Cider" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">cider</a>. Lead is considered to be particularly harmful for women's ability to reproduce. For that reason, many universities do not hand out lead-containing samples to women for instructional laboratory analyses.<sup class="noprint Template-Fact" style="line-height: 1em; "><span title="This claim needs references to reliable sources since February 2007" style="white-space: nowrap; ">[<i><a href="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">citation needed</a></i>]</span></sup> <a href="http://en.wikipedia.org/wiki/Lead(II)_acetate" title="Lead(II) acetate" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">Lead(II) acetate</a> (also known as <i>sugar of lead</i>) was used by the <a href="http://en.wikipedia.org/wiki/Roman_Empire" title="Roman Empire" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">Roman Empire</a> as a sweetener for wine, and some consider this to be the cause of the <a href="http://en.wikipedia.org/wiki/Dementia" title="Dementia" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">dementia</a> that affected many of the Roman Emperors.<sup id="cite_ref-17" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-17" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>18<span>]</span></a></sup></div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; ">Lead as a <a href="http://en.wikipedia.org/wiki/Soil_contaminant" title="Soil contaminant" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">soil contaminant</a> is a widespread issue, since lead is present in natural deposits and may also enter soil through (leaded) gasoline leaks from<a href="http://en.wikipedia.org/wiki/Underground_storage_tank" title="Underground storage tank" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">underground storage tanks</a> or through a wastestream of lead paint or lead grindings from certain industrial operations.</div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; ">Lead can also be found listed as a <a href="http://en.wikipedia.org/wiki/Criteria_pollutant" title="Criteria pollutant" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">criteria pollutant</a> in the <a href="http://en.wikipedia.org/wiki/United_States_Clean_Air_Act" title="United States Clean Air Act" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">United States Clean Air Act</a> section 108. Lead that is emitted into the atmosphere can be inhaled, or it can be ingested after it settles out of the air. It is rapidly absorbed into the bloodstream and is believed to have adverse effects on the central nervous system, the cardiovascular system, kidneys, and the immune system.<sup id="cite_ref-18" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Lead#cite_note-18" title="" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span>[</span>19<span>]</span></a></sup></div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><a name="Biochemistry_of_lead_poisoning" id="Biochemistry_of_lead_poisoning" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; "></a></div><h3 style="color: black; background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; font-weight: bold; margin-top: 0px; margin-right: 0px; margin-bottom: 0.3em; margin-left: 0px; padding-top: 0.5em; padding-bottom: 0.17em; border-bottom-width: initial; border-bottom-style: none; border-bottom-color: initial; font-size: 23px; background-position: initial initial; "><span class="editsection" style="float: right; margin-left: 5px; font-size: 17px; font-weight: normal; ">[<a href="http://en.wikipedia.org/w/index.php?title=Lead&action=edit&section=8" title="Edit section: Biochemistry of lead poisoning" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">edit</a>]</span><span class="mw-headline">Biochemistry of lead poisoning</span></h3><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; ">In the human body, lead inhibits <a href="http://en.wikipedia.org/wiki/Porphobilinogen_synthase" title="Porphobilinogen synthase" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">porphobilinogen synthase</a> and <a href="http://en.wikipedia.org/wiki/Ferrochelatase" title="Ferrochelatase" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">ferrochelatase</a>, preventing both <a href="http://en.wikipedia.org/wiki/Porphobilinogen" title="Porphobilinogen" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">porphobilinogen</a> formation and the incorporation of <a href="http://en.wikipedia.org/wiki/Iron" title="Iron" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">iron</a> into<a href="http://en.wikipedia.org/wiki/Protoporphyrin_IX" title="Protoporphyrin IX" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">protoporphyrin IX</a>, the final step in <a href="http://en.wikipedia.org/wiki/Heme" title="Heme" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">heme</a> synthesis. This causes ineffective heme synthesis and subsequent <a href="http://en.wikipedia.org/wiki/Microcytic_anemia" title="Microcytic anemia" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">microcytic anemia</a>.<sup class="noprint Template-Fact" style="line-height: 1em; "><span title="This claim needs references to reliable sources since March 2007" style="white-space: nowrap; ">[<i><a href="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; ">citation needed</a></i>]</span></sup> At lower levels, it acts as a calcium analog, interfering with ion channels during nerve conduction. This is one of the mechanisms by which it interferes with cognition.</div></div></span></div></body></html>