Lead is naturally occurring, highly toxic metal found in trace amounts deep in the Earth. Mining lead constitutes half of its annual production. Lead is used in numerous commercial industries due to its distinct physical and chemical nature. Although it has various beneficial uses, lead is toxic to humans, even at relatively low levels. For this reason, regulations monitoring lead production and exposure have continued to progress since the 1960s. Lead’s specific characteristics dictate its fate in the environment. Today, there are several sites in the US that currently present risks of exposure to lead. The EPA has implemented techniques to remediate lead present in public water supplies.
Nature and Production
Lead is a dense, naturally occurring
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metal found in relatively low concentrations in Earth’s crust (Lead in Water Information, 2004). Lead forms naturally by the radioactive decay of uranium and thorium through radon. In its purest form, lead is a lustrous, face-centered cubic crystal with no known allotropes. Lead is most commonly found in ores with zinc, silver, copper, and lead’s sulfide- galena (Acharya 894). Metallic lead is bluish-gray with no defining taste or smell and can form lead compounds or lead salts when it fuses with other chemicals (Lead in Water Information, 2004). About half of the annual production of lead comes from mining and the rest from recycling (Acharya 894). According to the United States Geological Survey (USGS), the United States is the third greatest miner of lead in the world behind China and Australia, mining 444,000 metric tons per year (Lead Production by Country). Lead ore is concentrated, fed into a sintering machine to burn off the sulfur and then smelted in conventional blast furnaces. It is refined using pyrometallurgical methods (Profile of the Nonferrous Metals Industry, 1995). Most recycled lead is used in batteries (Environmental Protection Agency, 1998). Commercial Uses Most lead found in the environment is the result of anthropogenic actions. In the past, lead was used in paint, automobile fuels, and plumbing and is still used today in batteries, alloys, and ammunition (Minnesota Pollution Control Agency, 1999). Lead is malleable, relatively soft, tensile, inflammable, resistant to corrosion unless exposed to air, and reacts quickly with hot acids (Alchin 2012). Lead is also used in TV and computer glass, construction, and protective coatings (Environmental Protection Agency, 1998). Due to its chemical and physical properties, lead is used in laboratories to line sinks and tanks, cover cables, support heavy machinery, and as a protective shield against X Rays and nuclear reactors emitting radiation (The Columbia Electronic Encyclopedia). Toxicity Lead is a highly toxic metal that poses serious risks to living organisms. In 1894, childhood lead poisoning was first discovered in Brisbane, Australia. Lead’s toxicity has since been studied and declared unsafe at various levels (Needleman 161). Lead interacts with proteins and mimics and inhibits the actions of calcium (U.S. Department of Health and Human Services). It enters the body through inhalation, ingestion, and dermal contact. The human nervous system is the most sensitive to lead. Inhaled lead present in the lower respiratory tract is mostly absorbed. The majority of lead that enters the body is excreted. Lead that is not excreted spreads through the body through blood, mineralizing tissue, and soft tissue. Blood is lead’s initial receptor. The half-life of lead in blood is estimated to be from 28-36 days. In mineralizing tissue, lead tends to collect in areas where the most active calcification is occurring during the exposure period. Lead also impedes the body’s ability to produce hemoglobin by obstructing numerous enzymatic processes in the heme pathway (U.S. Department of Health and Human Services). The hormonal form of vitamin D, which is primarily responsible for supporting extra- and intra- cellular calcium homeostasis, is impeded by lead. In pregnant women, lead in the blood can cross the placenta, endangering the fetus (Water-related Diseases). Encephalopathy, ataxia, coma, convulsions, death, hyperirritability, and stupor have been documented in children acutely exposed to lead at high levels. In workers acutely exposed to lead levels from 20-120 micrograms/dL, depression, diminished cognitive and visual motor performance, dizziness, impaired concentration, impotence, and reduced IQ scores have been reported (U.S. Department of Health and Human Services). Exposure to low levels of lead poses risks to human health.
As of 2006, the CDC has stated that lead should not exceed 10 micrograms/dl in children and 30 micrograms/dl in adults. The Occupational Health and Safety Agency has set a permissible exposure limit for lead in workplace air at 50 micrograms/dl averaged over an eight-hour workday. In uncontaminated soil, lead concentrations are less than 50 ppm. The EPA has set two standards for lead in soil. In play areas with bare soil, lead may not exceed 400 ppm by weight and 12000 ppm in non-play areas. In drinking water, the EPA’s maximum contaminant level goal is zero. However, the established action level for lead in drinking water is 15 micrograms/L. The FDA’s action level for lead in products designed for children and infants is 0.5 micrograms/mL (U.S. Department of Health and Human …show more content…
Services). Regulations In the 1960s, lead’s established toxic level in blood was 60 micrograms/deciliter in the US (Needleman 161). Today, numerous regulations exist limiting the amount of lead in water, paint, dust, air and soil. Under the Clean Water Act, it is illegal to discharge lead into water through a point source without a National Pollutant Discharge Elimination System (NPDES). For individuals with a NPDES, the EPA has issued 19 industry effluent guideline regulations that restrict lead discharges (Lead Regulations). Under the Lead and Copper Rule passed in June 1991, the EPA requires drinking water to be monitored at consumer taps. Section 1417 (a)(1) of the SDWA states that "no person may use any pipe, any pipe or plumbing fitting or fixture, any solder, or any flux, in the installation or repair of any public water system or any plumbing in a residential or nonresidential facility providing water for human consumption that is not lead free" (Lead and Copper Rule). EPA regulates lead in the air under the Clean Air Act through national ambient air quality standards (NAAQS) and National Emission Standards for Hazardous Air Pollutants (NESHAPs).
Lead in soil, dust, and paint is regulated by Title IV of the Toxic Substances Control Act (TSCA) and the Residential Lead-Based Paint Hazard Reduction Act of 1992 (Lead and Copper Rule). In 1977, lead was prohibited from consumer use paint. Between 1976 and 1996, gasoline containing tetraethyl lead was phased out (U.S. Department of Health and Human Services).
In the 1920s, the octane rating of gasoline was about 70. Tetraethyl lead was found to improve the octane rating of gasoline by slowing down the flame front’s movement through the combustion chamber. When the EPA established exhaust emission standards in 1975, companies decided to implement catalytic converters to reduce exhaust pollution. However, the lead in gasoline destroyed the catalyst’s ability. With the additional mounting medical data indicating that lead causes health problems in children, the EPA began phasing lead out of gasoline (Brown 94).
Characteristics Determining Distribution and Fate in
Environment Lead is relatively insoluble and is inflammable. In soil, lead is highly immobile (Minnesota Pollution Control Agency, 1999). As stated in the attached table, lead is malleable, ductile, and dense. Lead is found in galena, anglesite, and cerussite. When lead is exposed to air, it oxidizes and a coating of lead monoxide forms, protecting it from corrosion. Insoluble chloride or sulfate coatings form when lead is exposed to hydrochloric or sulfuric acids. This chemical resistance is what makes lead so popular in roofing materials, coverings for electric cables, and pipe linings. Hydrogen ions can oxidize lead to Pb+2 (Lead Pb, 2013). The table shows that the solubility of lead is 10 ppb above pH 8, while its solubility can reach or exceed 100 ppb near pH 6.5. Sites According to the Agency for Toxic Substances and Disease Registry, buildings built before 1978 in the US are the most widespread source of lead exposure in children, specifically through household dust (U.S. Department of Health and Human Services). Lead used in the paint of older buildings chips off walls and accumulates in dust. Lead was added to paint to speed up drying, increase durability, and resist moisture (Harding 2009). Near sites of continuing and historic mining operations or smelters, lead concentrations can be exceptionally higher in the soil, air, and water. In drinking water, especially hot water, lead leaches into water from pipes, faucets, and solder containing lead, specifically in homes built before 1986. Lead can be found in sites containing large mines, hazardous waste sites, garages working with old car batteries, lead smelting facilities, and workplaces involving lead (U.S. Department of Health and Human Services). One of the world’s largest historical mining districts is the Bunker Hill Superfund Site located in northern Idaho. In 1883, commercial mining for lead began in the area and Bunker Hill was added to the EPA’s National Priorities List of contaminated sites in 1983, after 100 years of soil, sediment, surface water, and groundwater contamination. In 1989, the percentage of children with blood lead levels greater than 10 micrograms/dl was about 52%. The EPA, the Idaho Department of Environmental Quality and the Panhandle Health District began working to remove lead contaminated soil and gravel. By 2002, the percentage of children with blood lead levels greater than 10 micrograms/dl was reduced to approximately 1% (Cleaning up Community Areas at the Bunker Hill Superfund Site). Today, some of the world’s largest lead deposits are located in southeast Missouri in an area commonly known as the Lead Belt. From the late 19th to early 20th century, Missouri was the international leader in lead production (Hazardous Waste Program). Throughout the region’s history, mining and milling processes have remained unchanged, using a room and pillar method. Waste rock is contained in a surface disposal area, causing environmental issues as tailings are wind-blown outside the waste management area. Trace elements from wastes and ore mineral concentrates and deposition from gases during smelting raise concern for local communities (Missouri Department of Natural Resources, 2008). In 1998, the Missouri Department of Natural Resources established a Natural Resource Damages (NRD) program under the Superfund Section of the Hazardous Waste Program. The NRD program is responsible for assessing injuries to public natural resources and restoring those that have been damaged by environmental hazards (Hazardous Waste Program). Limiting and Remediation The EPA has created a treatment technique, which is “an enforceable procedure or level of technological performance which water systems must follow to ensure control of a contaminant,” for lead. Water systems are required to collect samples from sites within the system. If more than 10% of tap water samples contain lead levels surpassing 15 ppb, the water system must take action, which includes replacing portions of lead service lines under its control (Basic Information about Lead in Drinking Water). Conclusion Lead is a highly toxic metal detrimental to human nervous systems, causing severe health effects in individuals both chronically and acutely exposed to relatively low levels. Lead has been used for centuries due to its chemical and physical properties that allowed it to be used in everything from paint, to batteries, to gasoline. As scientists began studying its harmful consequences, various regulations were put in place to monitor the dangerous element. Today, lead is regulated in the US, but residents in older buildings remain at risk to lead’s noxious results.
Regulations are created to protect the health and welfare of the public. The United States EPA develops the regulations at a federal level and each state’s EPA has the ability to make regulations pertaining to their state. The criteria for a state’s individual regulation are that it must be at least as strict as the federal regulation. The purpose of this paper is to examine the general requirements of the Lead and Copper Rule (with attention on the lead aspect) mandated to protect drinking water on the federal and state level.
This is why the Flint water crisis is so critical today. Because young children are being exposed to lead and they should actually be screened from the lead. The pipelines with lead in the water system and the whole community of Flint, not being able to drink water out of the facet as well as not being able to
Every underground gas tank eventually leaks, and the gasoline is soaked up by the surrounding ground. MTBE is not soluble in water; therefore, when the gasoline leaks out of the tank, the MTBE pollutes the ground water (well water), and eventually the surface water also. In addition, though MTBE reduces the amount of most pollutants released from automobiles, it also produces a harmful pollutant, formaldehyde, when combusted [CECA]. Even worse, a study performed by a medical researcher from the University of Pennsylvania, shows that MTBE may be the cause of a seventeen percent increase in asthma among kindergarten students since it has been utilized in gasoline. The study also shows that MTBE has failed to improve smog levels in the years it has been in use [Jones].
Lead is a metal found virtually everywhere even today. Sources of lead include auto body shops, electric storage batteries, glazes for china dishes, crockery, insecticides, electric cable insulation, hose, pipe, sheet and floor coverings. Lead is associated with stain glass work, jewelry making and antique ceramic doll painting. Although lead in paint was outlawed, there are still many homes that have lead paint (White et al, 1990). Lead found in gasoline was found in one study to account for 23--27% of the lead blood levels in the people tested (Wagner, 1991). This exposure to lead sources is more of a concern for children due to the characteristic habit of children to taste everything they touch; this characteristic is known as pica. Children are also in closer contact with their lead polluted environment during play. They are more active and exposed to outdoor contaminates and they inhale dust and dirt that are lead contaminated. Furthermore, the adsorption rate of lead in the digestive tract is up to 10 times greater in chil...
When lead enters the environment, it starts to become a problem. After a period of about ten days, depending on the weather, it falls to the surface. Here lead builds up in the soil particles. Where it may make its way into underground water or drinking water due to the fact the grounds acidic or if it's soft enough. Either way it stays a long time on the soil or in water. Months or years down the road after the lead has built up it starts to become a problem for children that play outside of their homes . This lead containing soil particles get on the child's hands or clothing and end up in the child's mouth. After the build up of so much lead it leads to lead poison. Lead poisoning has been an issue since the early 1900s, when the use of lead started being banned from the manufacturing of paint in foreign countries such as Australia. Unfortunately, the United States did not start banning it until 1978, when it finally became illegal in our nation. Today 90% of the lead in the atmosphere comes from the burning of gasoline. This problem has been a large issue since the 1920s, when the Environmental Protection Agency started making laws on the amount of lead allowed in gasoline.
chain. The use of lead in gasoline was phased out in '73 which caused lead
Huddie William Ledbetter also known as "Leadbelly" was an American folk singer and blues musical, most famous for his strong prominent vocals and his ability to play thetwelve-string guitar. Leadbellys astounding ability to play the guitar combined with his personal life experiences provided the foundation for his musical career. He also wrote about mainstream culture and black culture in general to express feelings of anger, sadness, and expose the wrongdoings of American society against blacks.
EPA. (2009, December 29). Retrieved January 15, 2011, from Toxicity and Exposure Assessment for Children's Health: http://www.epa.gov/teach/
... water crisis will have a long term affect on those who are consuming this water on a daily basis. Lead attack the brain and can cause coma and possibly death. Children who survive lead poisoning are left with serious health issues such as metal defects and leave a child mentally unstable. Even at lower levels of exposure symptoms such as behavioural changes such as reduced attention span, reduced intelligence quotient (IQ). Children with smaller amount of lead exposure also showed increased anti social behaviour, it also reduces educational attainment. These side effect of high lead exposure can leave children scarred for life. The water crisis in Flint Michigan car scar children for life. This could all be resolved if they could come to an agreement and replace the water pipes, allowing for cleaner and healthier water to be accessible to citizens in Flint Michigan.
The tradeoffs of using gasoline for cars are large emission of carbon dioxide and required large amount of chemical t...
Arsenic is the 20th most common element in the earth’s crust and can be found naturally in our environment. There is around 0.006 to 0.03 ppm or arsenic distributed in seawater, and 20 ppm of arsenic in soil (before pesticides). Every human will ingest about 0.5 to 1 mg of arsenic in a day from food and water, because arsenic is present in higher quantities in se...
Due to an above average level of poverty, many homes in New Orleans had very high levels of lead and arsenic in them. (Pastor) This combined with eighty percent of the city being flooded, released significant amounts of lead and arsenic into the environment which still exist today. Soil samples taken before and after Katrina showed elevated levels of lead, iron and arsenic. (Reible)A new study on one-hundred and nine households found that sixty-one percent had lead measurements above federal standards with twenty-seven percent greater than one-thousand two hundred ppm which was significantly higher than the five-hundred and sixty ppm collected before Hurricane Katrina. (Rabito) These inorganic compounds are related to cancer risks of which New Orleans already has a significant problem with. This complicates the decision on when and where to conduct environmental clean-ups in New Orleans to remove the lead, iron and arsenic.
Gasoline fueled cars produce a number of pollutants. The most damaging pollutants that come from gasoline fueled cars are particulate matter. Particulate matter is a sequence of organic materials and inorganic substances. It includes ingredients such as lint and minerals. Nitrogen dioxide, produced when fuel is burned at high temperatures, can cause damage to the lungs and cause chest pains. One might ask, “Why are Americans still driving gasoline cars?” knowing the damage that they are subject to cause. I personally maintain that the government should push people to p...
The Clean Air Act was passed by Congress in 1970, and was revised in 1977 and by 1990 to enlarge time limits, however, has specified new methodologies for cleaning the air. By enforcing new laws, the government will guarantee that the air ought to be cleaner and therefore make public health a framework. It has been indicated that the toxic lead emissions have dropped by 98% and the figure dioxide has dropped by 35%, even the carbon monoxide dropped by 32% (2010). One ought to begin by saying that the Clean Air Act is one of the few authoritative activities planned to diminish the vicinity of brown haze, carbon dioxide, and whatever viable environmental pollution by and large. The US Clear Air Act was passed by the United States Congress in 1963 and afterward would make various different acts to help the Clear Air Act: Clean Air Act Amendment of 1966, Clean Air Extension of 1970; Clean Air Act Amendment of 1977 and Clean Air Act Amendment of 1990.
Symptoms of lead poisoning include loss of appetite, weakness, anemia, vomiting, and convulsions, sometimes leading to permanent brain damage or death. Children who ingest chips of old, lead-containing paint or are exposed to dust from the deterioration of such paint may exhibit symptoms. Levels of environmental lead considered nontoxic may also be involved in increased hypertension in a significant number of persons, according to studies released in the mid-1980s. As a result, the U.S. Centers for Disease Control in recent years have been revising downward the levels of environmental lead that it would consider safe.