Top 10 Myths About Lead in Drinking Water
By Yanna Lambrinidou, PhD
It is an honor to be invited to write about lead in drinking water for LEAD Action NEWS, with lead poisoning prevention advocates Maria and Wayne Askew as guest editors. Although my knowledge about the subject is limited to the United States (US), I sincerely hope that at least some parts of this piece are useful to readers internationally.
The 10 myths below are preceded by a reflection on the social and political context of their creation and perpetuation. Out of concern that the existence of myths about a contaminant as hazardous as lead in drinking water can have serious public health and policy implications, and can exacerbate the environmental injustice that is already committed against communities across the US, I felt compelled to offer some thoughts on where the myths come from, and what role communities have played – and must continue to play – to correct them. This reflection is informed by my personal experience with Washington, DC’s historic lead-in-water crisis of 2001-2004; my work on the crisis’ aftermath since 2007; and my more recent collaboration through the Campaign for Lead Free Water with frontline communities in cities like Flint, Michigan; Milwaukee, Wisconsin; and Pittsburgh, Pennsylvania, working to address lead-in-water contamination problems of their own.
Although I hope that the context I provide can support and advance our work on the ground as well as perhaps the work on the ground of communities across the globe, this context is not necessary for making sense of the myths that follow. So, please, feel free to read it but also feel free to scroll directly to the 10 myths, below my reflection!
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In my ten years of work on lead in drinking water in the US, I have come to the conclusion that the problem is as much one of lead-bearing plumbing as it is of structurally manufactured ignorance. What I am referring to by this jargonistic term is officially sanctioned silence as well as dissemination of inaccurate, incomplete, or misleading information about the issue that the very institutions with the responsibility, authority, and power to protect us, systematically employ. The result is a public that, by and large, lacks the knowledge required not only to prevent exposures to lead in drinking water but also to recognize the existence, prevalence, and severity of the problem; appreciate its associated health risks; take action to correct it; and hold those responsible for it accountable.
The institutions manufacturing our ignorance include:
- Regulated public water utilities and the drinking water industry at large;
- Regulating government agencies, policymakers, and elected officials at the federal, state, and local government levels;
- School officials; and
- The medical, public health, and environmental health communities, including influential non-governmental organizations.
It is important to note that all these institutions speak as, and through, officially sanctioned experts; claim as their mission to protect the public’s health; and all, at least in theory, are dedicated to the prevention of childhood lead poisoning.
Three additional entities that often play a facilitating role in the cultivation of our ignorance are:
- Academic institutions and professional organizations, whose members tend to limit their participation in the matter to the production of specialized knowledge, shared primarily with groups other than affected publics (e.g., other academics, public water utilities and the drinking water industry, governmental institutions, and foundations);
- Funding bodies that refuse to sponsor projects on lead in water or sponsor projects led by groups with an established record of downplaying or obfuscating the problem; and
- The press, which frequently fails to carry out substantive or sustained reporting on the issue, or delivers official declarations uncritically and unquestioningly, even when these declarations are fundamentally incorrect.
It goes without saying that individuals within all of the above categories have at times taken decisive action to ensure that scientifically, historically, and legally accurate information is produced, publicly released, or adopted in policy recommendations or local interventions. In fact, the work and progress of affected communities so far would have been practically impossible without the contributions of dedicated government employees, drinking water quality experts, professionals in non-governmental organizations, and reporters willing to challenge the very foundations of the ignorance produced. Sadly, however, this informed resistance has had limited impact on how the institutions with the responsibility, authority, and power to protect us understand, respond to, and present the problem of lead in drinking water. More importantly, it has had limited impact on our ability to protect ourselves, as well as our fetuses, infants, and children from preventable, and yet irreparable, harm from lead at the tap.
In Agnotology: The Making & Unmaking of Ignorance historian of science Robert N. Proctor asserts that the production of collective ignorance can be conscious and unconscious, intentional and unintentional. Collective ignorance can be created and perpetuated by many different groups, formally organized and not. Its drivers can include multiple conditions – for example, “neglect, forgetfulness, myopia, extinction, secrecy, or suppression” (2008:3). Collective ignorance can feel “natural” both to those who promote it and to those who are subjected to it. It can cultivate in us a comfortable and comforting blindness. Perhaps most concerning is that collective ignorance can shape our understanding of matters that have significant effects on us – what historian and philosopher of science Kevin C. Elliot (2012) characterizes as “socially important.” Socially important ignorance can disempower us to act in our own best interests and can create the preconditions for exploitation, injustice, and harm.
A close examination of the recent history of lead in US drinking water reveals a recurring tension between, on the one hand, officially sanctioned narratives about the problem and, on the other, narratives of communities directly impacted by the problem. Community narratives are often generated in response to resident discoveries of lead-laced tap water or elevated blood lead levels from ingestion of such water. They are refusals to accept as “normal” experiences and observations that feel abnormal. They are at once articulations of distress and repositories of information that deviates from dominant understandings of reality. They are vehicles for protest where there was harmony, resistance where there was obedience, doubt where there was trust, and discomfort where there was comfort. They are demands for a “fix” that looks, feels, and measures like a fix. They are expressions of refusal to take for granted the “taken for granted,” even if the “taken for granted” is promoted and imposed by “the experts.”
Community narratives tend to question, complicate, expand, or oppose officially sanctioned narratives. Sometimes they go even further to challenge the trustworthiness of the creators and disseminators of officially sanctioned narratives. When this happens, community narratives signal decreasing willingness on the part of the public to accept the role of “non-knower” and to continue substituting its own judgments with the judgments of officially sanctioned experts (Hufford 1996). As a result, community narratives can pose a threat to the very authority of institutions that establish the dominant epistemic order (meaning, who can make knowledge and how knowledge ought to be made in order to be accepted as “valid”). Therefore, community narratives can pose a threat to the dominant social order as well. This is because institutional authority – and, by extension, status and power – necessitate the general public’s embrace of the idea that institutions hold superior knowledge, possess superior methods for developing this knowledge, and employ superior judgment for applying this knowledge to promote the public good.
Perhaps not surprisingly, community narratives tend to receive attenuated, if any, institutional credibility. The persistent and systematic rejection of information that a) comes from groups whose members our society deems to be “non-knowers,” and b) has the potential to change officially sanctioned paradigms of thought and practice, is a phenomenon that philosopher Miranda Fricker calls “testimonial injustice.” According to Fricker, this is “the injustice that a speaker suffers in receiving deflated credibility from the hearer owing to identity prejudice on the hearer’s part” (2007:Kindle Locations 100-101). Fricker characterizes testimonial injustice as an “epistemic disadvantage” to the hearer – “a moment of dysfunction in the overall epistemic practice or system.” Furthermore, she explains, “That testimonial injustice damages the epistemic system is directly relevant to social epistemologies […] for prejudice presents an obstacle to truth, either directly by causing the hearer to miss out on a particular truth, or indirectly by creating blockages in the circulation of critical ideas. Further, the fact that prejudice can prevent speakers from successfully putting knowledge into the public domain reveals testimonial injustice as a serious form of unfreedom in our collective speech situation – and […] the freedom of our speech situation is fundamental to the authority of the polity, even to the authority of reason itself” (2007:Kindle Locations 596-601).
The history of lead in US drinking water is marked by a long and still-growing chain of testimonial injustices committed against community groups in Washington, DC; Flint, MI; Milwaukee, WI; Pittsburgh, PA; and other cities in the country. These groups have, at one time or another, all challenged different components of the manufactured ignorance about the problem because they have refused to accept these components as “natural” (e.g., Carmody 2017, Bence 2017, Deprey 2017, Earthjustice 2017; Naccarati-Chapkis 2017, Milman 2016, Earthjustice et al. 2015, Lambrinidou 2015, Lambrinidou, Triantafyllidou, & Edwards 2010, Mitchell & Brion 2010, Alliance for Healthy Homes et al. 2008, Birnbaum 2008, Leonnig 2007, Holder 2004). In turn, they have often been discredited, silenced, or responded to in ways that seem to have done more to contain their politically disruptive potential than address their concerns.
What is especially important about the dynamic interplay of a) the structural cultivation of ignorance and b) the silencing of those who react against this ignorance is that it perpetuates and bolsters socially important beliefs about lead in US drinking water. These beliefs or myths have come to shape our society’s understanding of the problem and to form the cornerstone of related public policies, public messaging, public health decisions, medical practices, and drinking water use behaviors. I submit that as a result they have left, and continue to leave, generations of unsuspecting populations disempowered and needlessly at risk of irreversible harm from lead at the tap.
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The list of myths below is not exhaustive. It features only some of the most prevalent claims officially sanctioned experts in the US make about lead in drinking water.
Myth 1: Tap water that tests below 15 parts per billion (ppb) lead is safe for drinking and cooking.
Fifteen ppb lead is a technical threshold that was developed and adopted to act as a trigger for water utility compliance with regulatory requirements (Pupovac 2016). It was not meant as a health-based standard. In infants, for example, lead-in-water levels below 15 ppb have been predicted to raise blood lead levels in at least a small percentage of the exposed population (Triantafyllidou, Gallagher, & Edwards 2014). For lead in drinking water, the health-based goal set by the US Environmental Protection Agency (EPA) is zero ppb (EPA 2017), and the recommended health-protective standard set by the American Academy of Pediatrics (AAP) for lead in water in schools is 1 ppb (AAP 2016).
It is also important to note that lead levels in drinking water tend to fluctuate. Any lead-bearing plumbing component can release dramatically different concentrations of lead at different times and under different conditions. According to a recent study, “To adequately characterize whether water in a given home with lead plumbing is truly safe, a very high number of samples would have to be collected under a range of flow conditions” (Masters et al. 2016:13). Standard lead-in-water testing, however, involves one or, at most, two samples from a tap, and routinely misses worst-case lead levels. It is, therefore, possible that a drinking water outlet measuring below 15 ppb one time will dispense lead in the hundreds and thousands ppb at other times (Triantafyllidou & Edwards 2012).
For these two reasons – the toxicity of even low levels of lead in water and the fact that our testing methods are not designed to capture worst-case lead in drinking water – a tap measurement below 15 ppb does not signify that the water is safe for drinking or cooking. Yet the 15 ppb myth is perpetuated even by leading public health institutions like the US Centers for Disease Control and Prevention (CDC).
Myth 2: Tap water that meets federal lead-in-water requirements is safe for drinking and cooking.
In the US, federal lead-in-water requirements are embodied in the EPA regulation called the Lead and Copper Rule. For a city’s tap water to meet Lead and Copper Rule requirements, water utilities must take one sample from one tap at a small number of “high-risk” homes known to have either a lead service line (i.e., the pipe that connects a house to the water main under the street) or other lead-bearing plumbing prone to leach lead. For many major metropolitan utilities, for example, the minimum number of tap samples required from the entire system is as low as 50. If 90% or more of the samples collected measure below 15 ppb, the utility is deemed “in compliance” with the Lead and Copper Rule. Lead and Copper Rule compliance allows for up to 10% of taps to dispense any concentration of lead whatsoever. For example, in the latest Lead and Copper Rule test results it made public (July-Dec 2015), the Washington DC water utility took one sample from one tap at 110 homes and achieved regulatory compliance with the following results: 59 homes measured at 0 ppb; 50 homes measured between 1-8 ppb; and 1 home measured at 1,269 ppb. In other words, even when water utilities comply with the Lead and Copper Rule, the consumers they serve can experience both chronic and acute exposures to lead, without triggering a regulatory violation. Despite this fact, the EPA allows water utilities to declare their water “safe” for drinking and cooking, simply because they meet regulatory requirements (Q&A session, EPA Lead and Copper Rule stakeholder workshop, Washington DC, October 14-15, 2008).
Myth 3: Lead in drinking water is a “legacy” problem affecting only homes built before 1986.
In 1986, US Congress passed a law called the “Lead Ban,” which made illegal the use of pipes and pipe fittings containing more than 8% lead by weight. The Lead Ban also made illegal solder and flux containing more than 0.2% lead by weight. Plumbing materials meeting the Lead Ban’s new requirements were labeled under the law as “lead free.” Almost 30 years later, in 2014, Congress implemented a stricter definition of “lead free” by reducing the 8% lead-by-weight cap for pipes and pipe fittings to “a weighted average of 0.25% lead calculated across the wetted surfaces of a pipe, pipe fitting, plumbing fitting, and fixture” (EPA 2017). However, as the non-profit environmental law organization Earthjustice has pointed out, “The amount of lead tolerated under this definition depends on how the ‘weighted average’ is calculated. […] This averaging approach allows small components with significant amounts of lead to be cancelled out by other parts of a fixture or pipe that contribute a greater portion of the surface area” (Earthjustice et al. 2017).
- An estimated 6.5-10 million US homes have a lead service line containing 100% lead by weight (EPA 2016) (according to Triantafyllidou & Edwards 2012, lead service lines and lead pipes inside homes are even more prevalent in countries like France, the United Kingdom, Germany, and Portugal);
- An estimated 81 million US homes have lead solder containing 40-50% lead by weight (Triantafyllidou & Edwards 2012);
- US homes built between 1986-2013 have plumbing components containing up to 8% lead by weight; and
- US homes built since 2014 have plumbing components containing a weighted average of 0.25% lead calculated across their wetted surfaces.
Although homes built before 1986, especially those with lead service lines, are at very high risk for lead in drinking water, homes built after 1986 can also experience significant contamination (Triantafyllidou & Edwards 2012). In fact, recent evidence shows that in buildings with plumbing that meets the 2014 definition of “lead free,” taps can still dispense high levels of lead. Specifically, in 2016, testing at Flint, Michigan schools following removal of old plumbing and installation of new “lead free” fixtures showed lead-in-water concentrations that reached as high as 415 ppb.
Myth 4: All one needs to do to find out if there is lead in their tap water is to have their tap water tested.
Lead in drinking water appears in two forms: soluble lead (e.g., like salt or sugar dissolved in water) and lead particles (i.e., detached small pieces of lead-bearing rust, brass, solder, or pipes). Some lead particles can be large enough to be visible by the naked eye. Unlike soluble lead, lead particles can contain extraordinarily high concentrations of lead, reaching into the tens and hundreds of thousands ppb (water with lead levels over 5,000 ppb classifies as “hazardous waste”) (Triantafyllidou & Edwards 2012). Assessing lead-in-water problems where lead particles are present poses a serious challenge. Because lead particles tend to release erratically and unpredictably, “catching” them through standard sampling methods is often likened to a game of Russian roulette. In other words, lead particles can be – and are – easily missed. Moreover, because they can contain widely ranging concentrations of lead (their lead content can span from 3% to 100%), accurate determination of average lead levels from a single tap can require collection of hundreds and, in extreme cases, over 1,000 repeated samples (Masters et al., Power Point presentation, International Symposium on Inorganics, American Water Works Association, March 21-22, 2017). Yet standard testing for lead in drinking water involves one or, at most, two samples from a single tap. As a result, it routinely misses worst-case lead levels and often results in assumptions of “safety,” even when significant lead-in-water problems exist (Masters et al. 2016). It is worth noting that, according to a water utility industry funded study, if the sampling protocol used for Lead and Copper Rule compliance purposes were designed to capture worst-case lead from lead service lines, an estimated 70.5% of water utilities with such lines would exceed the Lead and Copper Rule’s 15 ppb threshold and would be legally required to take urgent remedial action (Slabaugh et al. 2015; Slabaugh, Power Point presentation, Water Quality Technology Conference, American Water Works Association, November 16-20, 2014).
Myth 5: For a child to get lead poisoning from tap water, they would need to drink an inordinate amount of this water every day.
Given that lead in drinking water can appear in the form of particles, and that such particles can contain extraordinarily high concentrations of lead, elevations of blood lead levels above (and far above) 5 and 10 micrograms per deciliter can occur, and have been extensively documented, in children who ingest ordinary amounts of lead-tainted water or eat ordinary amounts of food cooked with such water (Triantafyllidou, Parks, & Edwards 2007). In fact, when particles contain high enough levels of lead, children are predicted to experience acute blood lead level spiking even from a single 250 milliliter drink of water or a single portion of food cooked with 750 milliliters of water (Triantafyllidou, Gallagher, & Edwards 2014; Lambrinidou, Triantafyllidou, & Edwards 2010). In fact, exposure to lead particles with concentrations like those detected in 2011 in “City B” (580 ppb); in 2015 in Flint, Michigan (>5,000 ppb); and in 2015 in Washington DC (1,269 ppb) – all during periods of regulatory compliance with the Lead and Copper Rule – can expose pregnant women to a daily lead dose exceeding that in the lead abortion pills of the 1900s (Edwards 2014).
Myth 6: Unlike Flint, Michigan, most cities do treat their water with corrosion control so they are protected against lead-in-water contamination.
Corrosion control treatment aims at reducing the water’s ability to “eat away” at lead-bearing plumbing and cause contamination. Indeed, lead-in-water levels across the US have dropped markedly since the early 1990s due to the Lead and Copper Rule requirement that all large water utilities treat their water to reduce its corrosivity. Corrosion control treatment, however, has three significant limitations:
- It can reduce, but not entirely prevent, lead release into drinking water (e.g., Wasserstrom et al. 2017);
- It is markedly more successful at reducing soluble lead than lead particles. As a result, the “majority of lead in many distribution systems is now in a particulate form” (Masters et al. 2016:2); and
- It cannot eliminate conditions unrelated to the water’s corrosivity that encourage the release of lead from plumbing (e.g., age of plumbing; prolonged periods of stagnation due to lack of water use; routine low water use; hot water use; use of high water flow; increase in outside temperature; and physical disturbance of plumbing due to, for example, street work, renovations, or heavy traffic) (Lytle & Schock 2000; Del Toral, Porter, & Schock 2013; Masters et al. 2016). These conditions can dislodge small pieces of lead-bearing rust, brass, solder, or pipe, which can in turn pose an immediate and acute health risk to consumers analogous to lead paint (Lambrinidou 2015).
According to Triantafyllidou and Edwards, “The drinking water industry presently lacks the tools or knowledge to completely prevent or control particulate lead release” (2012:1318). Precisely because corrosion control treatment cannot, by itself, address the problem of lead in drinking water, water utility compliance with the Lead and Copper Rule allows for all monitored taps to dispense up to 15 ppb lead and up to 10% of monitored taps to dispense any concentration of lead whatsoever. Despite this allowance, water utilities can still fail to meet the Lead and Copper Rule’s 15 ppb threshold (e.g., Providence, Rhode Island; Jackson, Mississippi) (NRDC 2016).
Myth 7: Lead in drinking water can pose a problem only when the water has been sitting in lead-bearing plumbing for a long time. A quick flush before use will get rid of any contamination.
Prolonged stagnation of water in lead-bearing plumbing has, indeed, been shown to increase lead leaching (Lytle & Schock 2000). But there are conditions other than stagnation that can encourage corrosion of lead-bearing plumbing (e.g., intentional and unintentional changes in water chemistry; age of plumbing; hot water use; use of high water flow; increase in outside temperature; and physical disturbance of plumbing due to, for example, street work, renovations, or heavy traffic) (Edwards & Triantafyllidou 2007; Del Toral, Porter, & Schock 2013; Masters et al. 2016). Although flushing can, under certain circumstances, temporarily eliminate or partly reduce lead-in-water contamination, it cannot be relied upon to prevent exposures. First, if the home has a lead service line and the flush is not long enough, flushing prior to use can actually elevate the risk of exposure by bringing to the faucet the water that had prolonged contact with the lead service line (Del Toral, Porter, & Schock 2013). Second, because lead leaching, especially of lead particles, tends to occur unpredictably, flushing prior to use cannot guarantee that when the flush ends the water collected will be free of lead. In their discussion about the variability of lead release, Masters et al. (2016) assert that: “To adequately characterize whether water in a given home with lead plumbing is truly safe, a very high number of samples would have to be collected under a range of flow conditions. In some cases, it is desirable to characterize this risk in a given system, and in other cases, it would simply be more cost-effective to acknowledge that as long as lead-bearing plumbing is present, there is a significant risk of health hazards from semi-random concentrations of lead in water samples. These hazards can be partly reduced by flushing, but can be eliminated by installation of lead filters or removal of lead plumbing” (emphasis added).
Myth 8: Lead in drinking water is a problem of privately owned lead-bearing plumbing.
One of the most hazardous plumbing materials in existence is lead service lines, which are made of 100% pure lead and in some jurisdictions – like Chicago, Illinois and Milwaukee, Wisconsin – were mandated by law (Hawthorne & Matuszak 2016; Spicuzza 2016). In the majority of US jurisdictions, the utility owns the portion of a service line that lies between the water main and the property line, curb stop, or water meter (AWWA 2014). Legal ownership of the portion of a service line that lies between the property line, curb stop, or water meter and the home (i.e., in privately owned property) is often more difficult to determine but, in most cases, utilities or municipalities have control over the material composition and maintenance of this portion as well (1991 Lead and Copper Rule, 56 Fed. Reg. at 26504; Earthjustice 2014). Even when a home does not have a lead service line, however, attributing lead-in-water contamination to privately owned plumbing is misleading, for it implies that sole responsibility for the problem lies with homeowners. In reality, lead corrosion of plumbing materials is inextricably linked to drinking water corrosivity, and drinking water corrosivity is to a great degree – albeit not completely – controlled by water utilities. This link is the foundation of the Lead and Copper Rule. Additionally, the very fact that lead is added to plumbing materials to this day without consumer knowledge or approval renders consumer “blaming” for ownership of lead-bearing plumbing difficult to justify.
Myth 9: Lead in drinking water is almost never the primary source of lead poisoning.
Historical and scientific documentation illustrates clearly that lead in drinking water can, indeed, constitute the primary source of lead poisoning (Engel 1986; Renner 2006; Troesken 2006; Triantafyllidou & Edwards 2012). Moreover, the CDC estimates that 30% or more of elevated blood lead level cases in the US do not have an immediate lead paint source (Levin et al. 2008). But when children are diagnosed with elevated blood lead levels, environmental risk assessments at their homes are not designed to find lead at the tap. CDC’s case management guidelines recommend a focus on “immediate lead hazards,” pointing to deteriorating lead paint, dust, and soil (CDC 2009:23). The same guidelines insinuate that federal regulations to minimize lead in water (e.g., the Lead Ban, the Lead and Copper Rule) offer adequate public health protection. On the basis of this assumption, they suggest that environmental risk assessments at the homes of children with elevated blood lead levels forgo lead-in-water sampling unless:
- The tap water of the city where the children live exceeds the Lead and Copper Rule’s 15 ppb threshold; or
- No non-water sources of lead can be found in the children’s homes; or
- The water used for drinking and cooking in these homes comes from a well (well water is not regulated under the Lead and Copper Rule).
The same guidelines encourage any lead paint, dust, and soil identified in the children’s environments to be marked as the primary source of exposure, even if in reality the primary source is the drinking water. Moreover, when drinking water is actually tested, sampling techniques rarely – if ever – involve the extensive sampling required to capture erratically releasing lead particles. As a result, lead at the tap is routinely missed as the primary cause or a contributor to children’s elevated blood lead levels (Scott 2009; Renner 2009; Triantafyllidou & Edwards 2012).
Myth 10: The fact that blood lead monitoring data show dramatic declines in children’s blood lead levels over the years suggests that lead in drinking water does not pose a significant public health risk.
The preamble to the Lead and Copper Rule of 1991 states that, “…the total drinking water contribution to overall lead levels may range from as little as 5 percent to more than 50 percent of children’s total lead exposure. Infants dependent on formula may receive more than 85 percent of their lead from drinking water. As exposures decline to sources of lead other than drinking water, such as gasoline and soldered food cans, drinking water will account for a larger proportion of total intake” (1991 Lead and Copper Rule, 56 Fed. Reg. at 26470). To date, however, the US blood lead surveillance system does not include regular monitoring of fetuses’, infants’, or young children’s exposure to lead-laced tap water. Even though lead in drinking water has been found a) to be a primary source of lead exposure, and b) to cause miscarriage, fetal death, and elevated blood lead levels, systematic tracking of its presence in blood simply does not occur (Hanna-Attisha et al. 2016; Edwards 2014; Triantafyllidou & Edwards 2012; Edwards, Triantafyllidou, & Best 2009; Triantafyllidou, Parks, & Edwards 2007). In fact, the blood lead surveillance system currently in place misses both chronic and acute exposures to lead in drinking water. Specifically:
- The two most vulnerable populations to lead at the tap – fetuses and infants dependent on reconstituted formula – are rarely tested for lead in blood;
- A significant percentage of young children are never tested for lead in blood, and when they are tested their results often go unreported (Roberts et al. 2017); and
- Recommended strategies for blood lead testing are not designed to capture exposures to lead at the tap. Target children are around the ages of 1 and 2, prone to putting their hands in their mouth, and living in areas with housing presumed to contain deteriorating lead paint (Schneyer & Pell 2016). Moreover, the actual test involves a one-time blood draw that is repeated only when the result is deemed “high.” This approach does not account for the fact that the half-life of lead in blood is approximately one month. Unless the test occurs within a few days or weeks after exposure, blood lead elevations can be missed. This is especially problematic for exposure to lead particles, which can contain exceedingly high concentrations of lead and cause short but acute blood lead level spikes (Triantafyllidou & Edwards 2012).
In summary, current blood lead monitoring data cannot be relied upon to draw conclusions about the public health risk of lead in US drinking water.
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Acknowledgments: I thank Jennifer Chavez, JD; Paul Schwartz; and Tom Walker, PhD for their invaluable feedback on this document. Miguel Del Toral at US EPA, Marc Edwards, PhD at Virginia Tech, and Michael Schock at US EPA have been instrumental in teaching me about the science of lead corrosion and the workings of the Lead and Copper Rule. All opinions and any errors are my own.
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Yanna Lambrinidou, PhD, is affiliate faculty at the Department of Science and Technology in Society at Virginia Tech, President of Parents for Nontoxic Alternatives, and founding member of the Campaign for Lead Free Water. She can be reached at [email protected]