Concept: Lead poisoning
Human-induced rapid environmental change has created a global pandemic of neurobehavioral disorders in which industrial compounds like lead are the root cause. We assessed the feral pigeon (Columba livia) as a lead bioindicator in New York City. We collected blood lead level records from 825 visibly ill or abnormally behaving pigeons from various NYC neighborhoods between 2010 and 2015. We found that blood lead levels were significantly higher during the summer, an effect reported in children. Pigeon blood lead levels were not significantly different between years or among neighborhoods. However, blood lead levels per neighborhood in Manhattan were positively correlated with mean rates of lead in children identified by the NYC Department of Health and Mental Hygiene as having elevated blood lead levels (>10 μg/dl). We provide support for the use of the feral pigeon as a bioindicator of environmental lead contamination for the first time in the U.S. and for the first time anywhere in association with rates of elevated blood lead levels in children. This information has the potential to enable measures to assess, strategize, and potentially circumvent the negative impacts of lead and other environmental contaminants on human and wildlife communities.
We analyzed differences in pediatric elevated blood lead level incidence before and after Flint, Michigan, introduced a more corrosive water source into an aging water system without adequate corrosion control.
During April 25, 2014-October 15, 2015, approximately 99,000 residents of Flint, Michigan, were affected by changes in drinking water quality after their water source was switched from the Detroit Water Authority (DWA), sourced from Lake Huron, to the Flint Water System (FWS), sourced from the Flint River.* Because corrosion control was not used at the FWS water treatment plant, the levels of lead in Flint tap water increased over time. Adverse health effects are associated with lead exposure (1). On January 2, 2015, a water advisory was issued because of detection of high levels of trihalomethanes, byproducts of disinfectants.(†)(,)(§) Studies conducted by local and national investigators detected an increase in the prevalence of blood lead levels (BLLs) ≥5 µg/dL (the CDC reference level) among children aged <5 years living in Flint (2) and an increase in water lead levels after the water source switch (3). On October 16, 2015, the Flint water source was switched back to DWA, and residents were instructed to use filtered tap water for cooking and drinking. During that time, pregnant and breastfeeding women and children aged <6 years were advised to consume bottled water.(¶) To assess the impact on BLLs of consuming contaminated drinking water, CDC examined the distribution of BLLs ≥5 µg/dL among children aged <6 years before, during, and after the switch in water source. This analysis enabled determination of whether the odds of having BLLs ≥5 µg/dL before the switch differed from the odds during the switch to FWS (before and after the January 2, 2015, water advisory was issued), and after the switch back to DWA. Overall, among 9,422 blood lead tests in children aged <6 years, 284 (3.0%) BLLs were ≥5 µg/dL during April 25, 2013-March 16, 2016. The adjusted probability of having BLLs ≥5 µg/dL was 46% higher during the period after the switch from DWA to FWS (and before the January 2, 2015, water advisory) than during the period before the water switch to FWS. Although unrelated to lead in the water, the water advisory likely reduced tap water consumption and increased consumption of bottled water. Characterizing exposure to lead contaminated drinking water among children aged <6 years living in Flint can help guide appropriate interventions.
Objectives. We assessed the long-term effect of early childhood lead exposure on academic achievement in mathematics, science, and reading among elementary and junior high school children. Methods. We linked early childhood blood lead testing surveillance data from the Detroit Department of Health and Wellness Promotion to educational testing data from the Detroit, Michigan, public schools. We used the linked data to investigate the effect of early childhood lead exposure on academic achievement among school-aged children, both marginally and adjusted for grade level, gender, race, language, maternal education, and socioeconomic status. Results. High blood lead levels before age 6 years were strongly associated with poor academic achievement in grades 3, 5, and 8. The odds of scoring less than proficient for those whose blood lead levels were greater than 10 micrograms per deciliter were more than twice the odds for those whose blood lead levels were less than 1 micrograms per deciliter after adjustment for potential confounders. Conclusions. Early childhood lead exposure was negatively associated with academic achievement in elementary and junior high school, after adjusting for key potential confounders. The control of lead poisoning should focus on primary prevention of lead exposure in children and development of special education programs for students with lead poisoning. (Am J Public Health. Published online ahead of print January 17, 2013: e1-e6. doi:10.2105/AJPH.2012.301164).
The Coatzacoalcos Region in Veracruz, Mexico houses one of the most important industrial complexes in Mexico and Latin America. Lead is an ubiquitous environmental pollutant which represents a great risk to human health and ecosystems. Amphibian populations have been recognized as biomonitors of changes in environmental conditions. The purpose of this research is to measure exposure to lead and evaluate hematological and biochemical effects in specimens of giant toads (Rhinella marina) taken from three areas surrounding an industrial complex in the Coatzacoalcos River downstream. Lead levels in toads' blood are between 10.8 and 70.6 μg/dL and are significantly higher in industrial sites. We have found a significant decrease in the delta-aminolevulinic acid dehydratase (δ-ALAD) activity in blood from 35.3 to 78 % for the urban-industrial and industrial sites, respectively. In addition, we have identified a strong inverse relationship between the δ-ALAD activity and the blood lead levels (r = -0.84, p < 0.001). Hemoglobin and mean corpuscular hemoglobin levels, as well as the condition factor, are found to be lower at industrial sites compared with the reference sites. Our results suggest that the R. marina can be considered a good biomonitor of the δ-ALAD activity inhibition and hematological alterations at low lead concentrations.
The relation between Lead (Pb) and iron (Fe) becomes increasingly concerned because they are both divalent metals that are absorbed by the same intestinal mechanism, and Pb exposure and Fe deficiency in the developmental brain, as well as Fe overload in the aged brain, can cause cognitive deficits. However, the interaction between Pb exposure and Fe status in the brain has not been established. Therefore, in the current study, we examined the effects of maternal ingestion of Pb in drinking water during gestation and lactation on the Fe status and the expression of divalent metal transporter 1 (DMT1) and ferroportin 1 (FP1) in the brain of offspring. The offspring were followed through old age, with measurements taken at postnatal week 3, 41 and 70. Pb exposure increases the Fe content in the old-aged rats' brain, Which might be not subjected to DMT1 mediating, but may be associated with the decrease expression of FP1. Furthermore, the effect of Pb on FP1 expression is regulated at transcriptional and posttranscriptional levels. The perturbation in Fe homeostasis may contribute to the neurotoxicology consequences induced by Pb exposure, and FP1 may play a role in Pb-induced Fe cumulation in the brain.
This ecologic study notes that fetal death rates (FDR) during the Washington D.C. (DC) drinking water “lead crisis” (1997-2004) peaked in 2001 when water lead levels (WLLs) were highest, and were minimized in 2004 after public health interventions were implemented to protect pregnant women. Changes in the DC FDR vs. neighboring Baltimore City were correlated to DC WLL (R2 = 0.72). Birth rates in DC also increased versus Baltimore City and versus the United States in 2004-2006, when consumers were protected from high WLLs. The increased births in DC neighborhoods comparing 2004 versus 2001 was correlated to the incidence of lead pipes (R2 = 0.60). DC birth rates from 1999-2007 correlated with proxies for maternal blood lead including the geometric mean blood lead in DC children (R2 = 0.68) and the incidence of lead poisoning in children under age 1.3 years (R2 = 0.64). After public health protections were removed in 2006, DC FDR spiked in 2007-2009 versus 2004-2006 (p < 0.05), in a manner consistent with high WLL health risks to consumers arising from partial lead service line replacements, and DC FDR dropped to historically low levels in 2010-2011 after consumers were protected and the PSLR program was terminated. Re-evaluation of a historic construction-related miscarriage cluster in the USA Today Building (1987-1988), demonstrates that high WLLs from disturbed plumbing were a possible cause. Overall results are consistent with prior research linking increased lead exposure to higher incidence of miscarriages and fetal death, even at blood lead elevations (≈ 5 ug/dL) once considered relatively low.
Lead toxicity from retained bullet fragments is difficult to both predict and diagnose, but important to treat early, given the potential severity of disease. Blood lead levels > 25 μg/dL and 40 μg/dL are considered toxic in children and adults, respectively. Symptoms may range from nonspecific constitutional symptoms to seizures and coma. Chelation is the mainstay therapy for lead poisoning and levels to treat depend on patient age, blood lead levels, and the presence of symptoms. CASE REPORT: We present the case of a woman with symptoms of severe lead toxicity from 20-year-old retained bullet fragments. She had been seen by multiple providers for evaluation of each symptom, but a unifying diagnosis had not been found. After identifying this complication, she was treated appropriately and more serious complications were prevented. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: We present this case to increase awareness among emergency physicians of lead toxicity in patients with a seemingly unrelated constellation of symptoms and a history of a previous gunshot wound with retained bullet or bullet fragments.
- Reviews of environmental contamination and toxicology
- Published over 1 year ago
Lead is a persistent inorganic environmental pollutant that affects humans and animals worldwide. Avian species are especially susceptible to lead exposure through consumption of lead ammunition, lead fishing tackle, and other contaminated food sources such as aquatic species ingesting lead contaminated sediments in mining areas. Even with government regulations on the use of lead ammunition in many countries, including the United States, terrestrial, aquatic, predatory, and scavenger avian species are still at risk of exposure to potentially lethal concentrations of lead. The toxicities seen in these avian species include increased oxidative stress and decreased anti-oxidant enzymes in hepatic and renal tissue. The avian immune system is also a target of lead and displays a number of altered functions suggestive of immune suppression; however, studies in wildlife and laboratory species remain too limited for definitive statements with regard to population risk. In contrast, lead clearly inhibits reproductive capabilities in adult birds, and alters growth and development of hatchlings. Environmental remediation for lead removal, which would lower toxic exposure in wildlife, presently is a monumental and prohibitively expensive effort. Wildlife exposure will therefore continue in contaminated areas, necessitating development of new remediation practices. These plans should aim toward limiting more widespread or heavier contamination of wildlife habitats. This chapter reviews presently available information of lead toxicity in wild bird species, and suggests continued monitoring and reduction strategies to reduce lead exposure for at-risk avian populations.
An estimated 115,000 firearm injuries occur annually in the United States, and approximately 70% are nonfatal (1). Retained bullet fragments (RBFs) are an infrequently reported, but important, cause of lead toxicity; symptoms are often nonspecific and can appear years after suffering a gunshot wound (2,3). Adult blood lead level (BLL) screening is most commonly indicated for monitoring of occupational lead exposure; routine testing of adults with RBFs is infrequent (3). States collaborate with CDC’s National Institute for Occupational Safety and Health (NIOSH) to monitor elevated BLLs through the Adult Blood Lead Epidemiology and Surveillance (ABLES) program (4,5). To help assess the public health burden of RBFs, data for persons with BLLs ≥10 μg/dL reported to ABLES during 2003-2012 were analyzed. An RBF-associated case was defined as a BLL ≥10 μg/dL in a person with an RBF. A non-RBF-associated case was defined as a BLL ≥10 μg/dL without an RBF. During 2003-2012, a total of 145,811 persons aged ≥16 years with BLLs ≥10 μg/dL were reported to ABLES in 41 states. Among these, 457 RBF-associated cases were identified with a maximum RBF-associated BLL of 306 μg/dL. RBF-associated cases accounted for 0.3% of all BLLs ≥10 μg/dL and 4.9% of BLLs ≥80 μg/dL. Elevated BLLs associated with RBFs occurred primarily among young adult males in nonoccupational settings. Low levels of suspicion of lead toxicity from RBFs by medical providers might cause a delay in diagnosis (3). Health care providers should inquire about an RBF as the potential cause for lead toxicity in an adult with an elevated BLL whose lead exposure is undetermined.