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1.
PNAS Nexus ; 2(1): pgac285, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36712926

ABSTRACT

Lead-formulated aviation gasoline (avgas) is the primary source of lead emissions in the United States today, consumed by over 170,000 piston-engine aircraft (PEA). The U.S. Environmental Protection Agency (EPA) estimates that four million people reside within 500m of a PEA-servicing airport. The disposition of avgas around such airports may be an independent source of child lead exposure. We analyze over 14,000 blood lead samples of children (≤5 y of age) residing near one such airport-Reid-Hillview Airport (RHV) in Santa Clara County, California. Across an ensemble of tests, we find that the blood lead levels (BLLs) of sampled children increase in proximity to RHV, are higher among children east and predominantly downwind of the airport, and increase with the volume of PEA traffic and quantities of avgas sold at the airport. The BLLs of airport-proximate children are especially responsive to an increase in PEA traffic, increasing by about 0.72 µg/dL under periods of maximum PEA traffic. We also observe a significant reduction in child BLLs from a series of pandemic-related interventions in Santa Clara County that contracted PEA traffic at the airport. Finally, we find that children's BLLs increase with measured concentrations of atmospheric lead at the airport. In support of the scientific adjudication of the EPAs recently announced endangerment finding, this in-depth case study indicates that the deposition of avgas significantly elevates the BLLs of at-risk children.

2.
Article in English | MEDLINE | ID: mdl-35206622

ABSTRACT

By the end of spring (31 May), the COVID-19 death rate was remarkably unevenly distributed across the countries in Europe. While the risk of COVID-19 mortality is known to increase with age, age-specific COVID-19 death rates across Europe were similarly unevenly distributed. To explain these mortality distributions, we present a simple model where more favorable survival environments promote longevity and the accumulation of health frailty among the elderly while less favorable survival environments induce a mortality selection process that results in lower health frailty. Because the age-related conditions of frailty render the elderly less resistant to SARS-CoV-2, pre-existing survival environments may be non-obviously positively related to the COVID-19 death rate. To quantify the survival environment parameter of our model, we leveraged historic cohort- and period-based age-specific probabilities of death and life expectancies at age 65 across Europe. All variables are significantly correlated with indicators of frailty like elderly dependence on others for personal and household care for a subset of European countries. With respect to COVID-19 death rates, we find significant positive relationships between our survival indicators and COVID-19 death rates across Europe, a result that is robust to statistical control for the capacity of a healthcare system to treat and survive infected persons, the timing and stringency of non-pharmaceutical interventions, population density, age structure, case rates and the volume of inbound international travelers, among other factors. To address possible concerns over reporting heterogeneity across countries, we show that results are robust to the substitution of our response variable for a measure of cumulative excess mortality. Also consistent with the intuition of our model, we also show a strong negative association between age-specific COVID-19 death rates and pre-existing all-cause age-specific mortality rates for a subset of European countries. Overall, results support the notion that variation in pre-existing frailty, resulting from heterogeneous survival environments, partially accounts for striking differences in COVID-19 death during the first wave of the pandemic.


Subject(s)
COVID-19 , Frailty , Aged , Europe/epidemiology , Frailty/epidemiology , Humans , Longevity , SARS-CoV-2
3.
Health Econ Policy Law ; 17(3): 247-265, 2022 07.
Article in English | MEDLINE | ID: mdl-33517937

ABSTRACT

Analyzing whether physicians use cesarean sections (c-sections) as defensive medicine (DM) has proven difficult. Using natural experiments arising out of Oregon court decisions overturning a state legislative cap on non-economic damages in tort cases, we analyze the impact of patient conditions on estimates of DM. Consistent with theory, we find heterogeneous impacts of tort laws across patient conditions. When medical exigencies dictate a c-section, tort laws have no impact on physician decisions. When physicians have latitude in their decision making, we find evidence of DM. When we estimate a model combining all women and not accounting for patient conditions (such as models estimated in previous studies) we obtain a result which is the opposite of DM, which we call offensive medicine (OM). The OM result appears to arise out of a bias in the difference-in-differences estimator associated with changes in the marginal distributions of patient conditions in control and treatment groups. The changes in the marginal distributions appear to arise from the impact of tort law on the market for midwives (substitutes for physicians for low-risk women). Our analysis suggests that not accounting for theoretically expected heterogeneity in physician reactions to changes in tort laws may produce biased estimates of DM.


Subject(s)
Malpractice , Physicians , Cesarean Section , Defensive Medicine , Female , Humans , Liability, Legal , Pregnancy , United States
4.
Environ Res ; 181: 108928, 2020 02.
Article in English | MEDLINE | ID: mdl-31787215

ABSTRACT

In February of 2016, the City of Flint, Michigan commenced the FAST start initiative with the aim "to get the lead out of Flint" by replacing lead and galvanized steel service lines throughout the city. An estimated 29,100 parcels are scheduled for service line replacement (SLR) at an expected cost of $172 million. The lead exposure benefits of SLR are evaluated by analyzing Sentinel data on hundreds of repeatedly sampled homes in Flint from February 16, 2016 to July 21, 2017, comparing water lead (WL) in homes with and without lead service lines. Samples taken from homes with lead service lines were significantly more likely to exceed specified thresholds of WL than homes without lead service lines. Second, regardless of service line material type, sampled homes experienced significant reductions in WL with elapsed time from Flint's switchback to water provided by the Detroit Water and Sewage Department. Third, the risk of exceedance of WL > 15 µg/L was uncorrelated with service line material type. These results are robust to sample restrictions, period stratification, time operations, reference group definitions, and statistical modeling procedures. On the question of what is gained from SLR over optimal corrosion control techniques, we simulated age-specific lead uptake (µg/day) and blood lead levels (µg/dL) for children in Flint at 16 and 90 weeks of elapsed time from Flint's switchback to Detroit water. At 90 weeks from the switchback in water source, the quantity of water lead consumed by children in homes with lead service lines decreased 93%, as compared to 16 weeks. Lead exposure benefits of SLR have declined in time, with modest differences in lead uptake across homes with different service lines. In light of results, policy considerations for Flint and nationwide are discussed.


Subject(s)
Drinking Water , Lead , Water Pollutants, Chemical , Child , Cities , Humans , Michigan , Water Supply
5.
Risk Anal ; 39(7): 1476-1490, 2019 07.
Article in English | MEDLINE | ID: mdl-30675917

ABSTRACT

The establishment of interventions to maximize maternal health requires the identification of modifiable risk factors. Toward the identification of modifiable hospital-based factors, we analyze over 2 million births from 2005 to 2010 in Texas, employing a series of quasi-experimental tests involving hourly, daily, and monthly circumstances where medical service quality (or clinical capital) is known to vary exogenously. Motivated by a clinician's choice model, we investigate whether maternal delivery complications (1) vary by work shift, (2) increase by the hours worked within shifts, (3) increase on weekends and holidays when hospitals are typically understaffed, and (4) are higher in July when a new cohort of residents enter teaching hospitals. We find consistent evidence of a sizable statistical relationship between deliveries during nonstandard schedules and negative patient outcomes. Delivery complications are higher during night shifts (OR = 1.21, 95% CI: 1.18-1.25), and on weekends (OR = 1.09, 95% CI: 1.04-1.14) and holidays (OR = 1.29, 95% CI: 1.04-1.60), when hospitals are understaffed and less experienced doctors are more likely to work. Within shifts, we show deterioration of occupational performance per additional hour worked (OR = 1.02, 95% CI: 1.01-1.02). We observe substantial additional risk at teaching hospitals in July (OR = 1.28, 95% CI: 1.14-1.43), reflecting a cohort-turnover effect. All results are robust to the exclusion of noninduced births and intuitively falsified with analyses of chromosomal disorders. Results from our multiple-test strategy indicate that hospitals can meaningfully attenuate harm to maternal health through strategic scheduling of staff.


Subject(s)
Delivery, Obstetric/adverse effects , Obstetrics/organization & administration , Personnel Staffing and Scheduling , Algorithms , Female , Holidays , Hospitals/statistics & numerical data , Humans , Labor, Obstetric , Medical Errors , Outcome Assessment, Health Care , Patient Admission/statistics & numerical data , Pregnancy , Risk Factors , Texas , Work Schedule Tolerance
6.
Environ Int ; 122: 91-103, 2019 01.
Article in English | MEDLINE | ID: mdl-30509512

ABSTRACT

BACKGROUND: Broken Hill is home to Australia's oldest silver-zinc-lead mine. However, the precise source of childhood blood lead (PbB) exposures has been subject to considerable debate. Lead sources include natural soil Pb enrichment, legacy deposition, contemporary mining emissions, and Pb-based paint. OBJECTIVE: To test whether contemporary mining emissions independently affect childhood PbB in Broken Hill. METHODS: Children's (<5 years old) PbB measures from 2011 to 2015 (n = 4852), obtained from Broken Hill Child & Family Health Centre, were analyzed using generalised linear regression models, including covariates of household soil Pb, city dust Pb concentrations (PbD), demographic factors and Pb ore production. Two natural experiments involving wind direction and the 2009 dust storm were examined to test whether the PbB-distance gradient from the mining operations was influenced by contemporary emissions. The influence of contemporary emissions was further interrogated by examining the effect of ore production on PbB and PbD. RESULTS: Children living downwind and proximate to the mine had substantially higher PbB outcomes than children similarly distant but upwind. Dust Pb deposition increased significantly with proximity to mining operations as well to Pb production (1991-2013). Average annual PbB correlated with Pb ore production (p < 0.01) with all subsets of children PbB levels responding with near unit elasticity to Pb ore production (p < 0.01). Pre- and post-analysis of the dust storm showed the PbB-distance gradient remained statistically unaltered further confirming contemporary emissions as a source of exposure. CONCLUSIONS: Contemporary mining emissions influence children's PbB measures independent of other sources and need to be remediated to facilitate reductions in harmful exposure.


Subject(s)
Environmental Exposure/analysis , Lead/blood , Mining , Australia , Child , Child, Preschool , Dust/analysis , Female , Humans , Male , Silver , Soil , Zinc
7.
Proc Natl Acad Sci U S A ; 115(8): E1730-E1739, 2018 02 20.
Article in English | MEDLINE | ID: mdl-29432149

ABSTRACT

The 2014-2015 Legionnaires' disease (LD) outbreak in Genesee County, MI, and the outbreak resolution in 2016 coincided with changes in the source of drinking water to Flint's municipal water system. Following the switch in water supply from Detroit to Flint River water, the odds of a Flint resident presenting with LD increased 6.3-fold (95% CI: 2.5, 14.0). This risk subsided following boil water advisories, likely due to residents avoiding water, and returned to historically normal levels with the switch back in water supply. During the crisis, as the concentration of free chlorine in water delivered to Flint residents decreased, their risk of acquiring LD increased. When the average weekly chlorine level in a census tract was <0.5 mg/L or <0.2 mg/L, the odds of an LD case presenting from a Flint neighborhood increased by a factor of 2.9 (95% CI: 1.4, 6.3) or 3.9 (95% CI: 1.8, 8.7), respectively. During the switch, the risk of a Flint neighborhood having a case of LD increased by 80% per 1 mg/L decrease in free chlorine, as calculated from the extensive variation in chlorine observed. In communities adjacent to Flint, the probability of LD occurring increased with the flow of commuters into Flint. Together, the results support the hypothesis that a system-wide proliferation of legionellae was responsible for the LD outbreak in Genesee County, MI.


Subject(s)
Disease Outbreaks , Drinking Water/microbiology , Legionella pneumophila/isolation & purification , Legionnaires' Disease/epidemiology , Water Microbiology , Water Supply , Chlorine , Drinking Water/chemistry , Humans , Michigan/epidemiology , Risk Factors
8.
Environ Res ; 157: 160-172, 2017 08.
Article in English | MEDLINE | ID: mdl-28570960

ABSTRACT

The Flint Water Crisis (FWC) is divisible into four phases of child water-lead exposure risk: Phase A) before the switch in water source to the Flint River (our baseline); Phase B) after the switch in water source, but before boil water advisories; Phase C) after boil water advisories, but before the switch back to the baseline water source of the Detroit Water and Sewerage Department (DWSD); and Phase D) after the switch back to DWSD. The objective of this work is to estimate water-lead attributable movements in child blood lead levels (BLLs) that correspond with the four phases in the FWC. With over 21,000 geo-referenced and time-stamped blood lead samples from children in Genesee County drawn from January 01, 2013 to July 19, 2016, we develop a series of quasi-experimental models to identify the causal effect of water-lead exposure on child BLLs in Flint. We find that the switch in water source (transitioning from phase A to B) caused mean BLLs to increase by about 0.5µg/dL, and increased the likelihood of a child presenting with a BLL ≥ 5µg/dL by a factor of 1.91-3.50, implying an additional 561 children exceeding 5µg/dL. We conservatively estimate cohort social costs (through lost earnings alone) of this increase in water-lead exposed children at $65 million, contrasted with expected annual savings of $2 million from switching water source. On the switch from Phase B to C, we find BLLs decreased about 50% from their initial rise following boil water advisories and subsequent water avoidance behaviors by households. Finally, the return to the baseline source water (Phase D) returned child BLLs to pre-FWC levels further implicating water-lead exposure as a causal source of child BLLs throughout the FWC.


Subject(s)
Drinking Water/analysis , Environmental Exposure , Lead Poisoning/blood , Water Pollutants, Chemical/poisoning , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Lead Poisoning/etiology , Male , Michigan , Risk Factors , Water Pollutants, Chemical/blood
9.
Environ Res ; 153: 181-190, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27992849

ABSTRACT

BACKGROUND: The age standardized death rate from motor neuron disease (MND) for persons 40-84 years of age in the Australian States of New South Wales, Victoria, and Queensland increased dramatically from 1958 to 2013. Nationally, age-specific MND death rates also increased over this time period, but the rate of the rise varied considerably by age-group. The historic use of lead (Pb) additives in Australian petrol is a candidate explanation for these trends in MND mortality (International Classification of Disease (ICD)-10 G12.2). METHODS: Leveraging temporal and spatial variation in petrol lead exposure risk resulting from the slow rise and rapid phase-out of lead as a constituent in gasoline in Australia, we analyze relationships between (1) national age-specific MND death rates in Australia and age-specific lifetime petrol lead exposure, (2) annual between-age dispersions in age-specific MND death rates and age-specific lifetime petrol lead exposure; and (3) state-level age-standardized MND death rates as a function of age-weighted lifetime petrol lead exposure. RESULTS: Other things held equal, we find that a one percent increase in lifetime petrol lead exposure increases the MND death rate by about one-third of one percent in both national age-specific and state-level age-standardized models of MND mortality. Lending support to the supposition that lead exposure is a driver of MND mortality risk, we find that the annual between-age group standard deviation in age-specific MND death rates is strongly correlated with the between-age standard deviation in age-specific lifetime petrol lead exposure. CONCLUSION: Legacy petrol lead emissions are associated with age-specific MND death rates as well as state-level age-standardized MND death rates in Australia. Results indicate that we are approaching peak lead exposure-attributable MND mortality.


Subject(s)
Environmental Exposure/adverse effects , Gasoline , Lead/toxicity , Motor Neuron Disease/mortality , Adult , Aged , Aged, 80 and over , Australia/epidemiology , Environmental Exposure/analysis , Humans , Middle Aged , Motor Neuron Disease/chemically induced
10.
Environ Pollut ; 207: 345-56, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26448503

ABSTRACT

Arsenic, cadmium and lead in aerosols, dusts and surface soils from Australia's oldest continuous lead mining town of Broken Hill were compared to standardised national childhood developmental (year 1) and education performance measures (years 3,5,7,9). Contaminants close to mining operations were elevated with maximum lead levels in soil: 8900 mg/kg; dust wipe: 86,061 µg/m(2); dust deposition: 2950 µg/m(2)/day; aerosols: 0.707 µg/m(3). The proportion of children from Broken Hill central, the area with the highest environmental contamination, presented with vulnerabilities in two or more developmental areas at 2.6 times the national average. Compared with other school catchments of Broken Hill, children in years 3 and 5 from the most contaminated school catchment returned consistently the lowest educational scores. By contrast, children living and attending schools associated with lower environmental contamination levels recorded higher school scores and lower developmental vulnerabilities. Similar results were identified in Australia's two other major lead mining and smelting cities of Port Pirie and Mount Isa.


Subject(s)
Aerosols/chemistry , Dust/analysis , Environmental Pollutants/analysis , Environmental Pollution/adverse effects , Mining , Soil/chemistry , Arsenic/analysis , Australia , Behavior , Cadmium/analysis , Child , Child, Preschool , Cities , Education , Environmental Monitoring , Environmental Pollution/statistics & numerical data , Humans , Lead/analysis
11.
Environ Pollut ; 202: 112-9, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25818090

ABSTRACT

Washing and wet mopping is often advocated as a remedial treatment to limit exposure to lead dust. Here, surface and pre- and post-play wipes were measured to ascertain dust metal exposures (arsenic, cadmium, copper, lead and zinc) following play routines at four playgrounds in the smelter city of Port Pirie, South Australia, which are washed regularly. Although post-play hand wipe metals were 55.9% (95% CI: -0.78, -0.34) lower on wash days, loadings increased ∼5.1% (95% CI: 1.2, 11.7) per hour after washing. Despite washing, post-play hand lead exceeded a conservative value of 800 µg/m(2) within 24 h or sooner, with loadings increasing in proximity to the smelter. Post-play lead loadings were always >1000 µg/m(2) at the playground closest to smelter. Playground washing results in short-lived exposure reduction and effective treatment requires elimination of smelter emissions.


Subject(s)
Dust/analysis , Environmental Exposure/prevention & control , Environmental Pollutants/analysis , Environmental Restoration and Remediation/methods , Metals, Heavy/analysis , Play and Playthings , Humans , South Australia
12.
Proc Natl Acad Sci U S A ; 112(9): E928-36, 2015 Mar 03.
Article in English | MEDLINE | ID: mdl-25730846

ABSTRACT

Research links psychosocial stress to premature telomere shortening and accelerated human aging; however, this association has only been demonstrated in so-called "WEIRD" societies (Western, educated, industrialized, rich, and democratic), where stress is typically lower and life expectancies longer. By contrast, we examine stress and telomere shortening in a non-Western setting among a highly stressed population with overall lower life expectancies: poor indigenous people--the Sahariya--who were displaced (between 1998 and 2002) from their ancestral homes in a central Indian wildlife sanctuary. In this setting, we examined adult populations in two representative villages, one relocated to accommodate the introduction of Asiatic lions into the sanctuary (n = 24 individuals), and the other newly isolated in the sanctuary buffer zone after their previous neighbors were moved (n = 22). Our research strategy combined physical stress measures via the salivary analytes cortisol and α-amylase with self-assessments of psychosomatic stress, ethnographic observations, and telomere length assessment [telomere-fluorescence in situ hybridization (TEL-FISH) coupled with 3D imaging of buccal cell nuclei], providing high-resolution data amenable to multilevel statistical analysis. Consistent with expectations, we found significant associations between each of our stress measures--the two salivary analytes and the psychosomatic symptom survey--and telomere length, after adjusting for relevant behavioral, health, and demographic traits. As the first study (to our knowledge) to link stress to telomere length in a non-WEIRD population, our research strengthens the case for stress-induced telomere shortening as a pancultural biomarker of compromised health and aging.


Subject(s)
Indians, North American/genetics , Longevity/genetics , Stress, Psychological , Telomere Homeostasis/genetics , Telomere/genetics , Adult , Female , Humans , Hydrocortisone/metabolism , Male , Stress, Psychological/genetics , Stress, Psychological/metabolism , Stress, Psychological/pathology , Telomere/metabolism
13.
J Reg Sci ; 55(4): 560-584, 2015 Sep.
Article in English | MEDLINE | ID: mdl-27516625

ABSTRACT

We examine the contribution to economic growth of entrepreneurial "marketplace information" within a regional endogenous growth framework. Entrepreneurs are posited to provide an input to economic growth through the information revealed by their successes and failures. We empirically identify this information source with the regional variation in establishment births and deaths, which create geographic information asymmetries that influence subsequent entrepreneurial activity and economic growth. We find that local establishment birth and death rates are significantly and positively correlated with subsequent entrepreneurship for US counties. To account for the potential endogeneity caused by forward-looking entrepreneurs, we utilize instruments based on historic mining activity. We find that the information spillover component of local establishment birth and death rates have significant positive effects on subsequent entrepreneurship and employment growth for US counties and metropolitan areas. With the help of these intruments, we show that establishment births have a positive and significant effect on future employment growth within all counties, and that in line with the information hypothesis, local establishment death rates have a similar positive effect within metropolitan counties.

14.
Environ Res ; 133: 274-81, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24981826

ABSTRACT

BACKGROUND: Previous studies link maternal blood lead (Pb) levels and pregnancy-related hypertensive disorders. OBJECTIVE: Assess the relationship between neighborhood soil Pb and maternal eclampsia risk. METHODS: Zip code summarized high density soil survey data of New Orleans collected before and after Hurricanes Katrina and Rita (HKR) were merged with pregnancy outcome data on 75,501 mothers from the Louisiana office of public health. Cross-sectional logistic regression analyses are performed testing the association between pre-HKR accumulation of Pb in soils in thirty-two neighborhoods and eclampsia risk. Then we examine whether measured declines in soil Pb following the flooding of the city resulted in corresponding reductions of eclampsia risk. RESULTS: Cross-sectional analyses show that a one standard deviation increase in soil Pb increases the odds of eclampsia by a factor of 1.48 (95% CI: 1.31, 1.66). Mothers in zip code areas with soil Pb>333 mg/kg were 4.00 (95% CI: 3.00, 5.35) times more likely to experience eclampsia than mothers residing in neighborhoods with soil Pb<50mg/kg. Difference-in-differences analyses capturing the exogenous reduction in soil Pb following the 2005 flooding of New Orleans indicate that mothers residing in zip codes experiencing decrease in soil Pb (-387.9 to -33.6 mg/kg) experienced a significant decline in eclampsia risk (OR=0.619; 95% CI: 0.397, 0.963). CONCLUSIONS: Mothers residing in neighborhoods with high accumulation of Pb in soils are at heightened risk of experiencing eclampsia.


Subject(s)
Eclampsia/chemically induced , Environmental Exposure/adverse effects , Lead/toxicity , Maternal Exposure/adverse effects , Soil Pollutants/toxicity , Cross-Sectional Studies , Eclampsia/epidemiology , Female , Floods , Humans , New Orleans/epidemiology , Population Dynamics , Pregnancy , Pregnancy Outcome
15.
J Epidemiol Community Health ; 68(8): 760-6, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24811774

ABSTRACT

BACKGROUND: The majority of research documenting the public health impacts of natural disasters focuses on the well-being of adults and their living children. Negative effects may also occur in the unborn, exposed to disaster stressors when critical organ systems are developing and when the consequences of exposure are large. METHODS: We exploit spatial and temporal variation in hurricane behaviour as a quasi-experimental design to assess whether fetal death is dose-responsive in the extent of hurricane damage. Data on births and fetal deaths are merged with Parish-level housing wreckage data. Fetal outcomes are regressed on housing wreckage adjusting for the maternal, fetal, placental and other risk factors. The average causal effect of maternal exposure to hurricane destruction is captured by difference-in-differences analyses. RESULTS: The adjusted odds of fetal death are 1.40 (1.07-1.83) and 2.37 (1.684-3.327) times higher in parishes suffering 10-50% and >50% wreckage to housing stock, respectively. For every 1% increase in the destruction of housing stock, we observe a 1.7% (1.1-2.4%) increase in fetal death. Of the 410 officially recorded fetal deaths in these parishes, between 117 and 205 may be attributable to hurricane destruction and postdisaster disorder. The estimated fetal death toll is 17.4-30.6% of the human death toll. CONCLUSIONS: The destruction caused by Hurricanes Katrina and Rita imposed significant measurable losses in terms of fetal death. Postdisaster migratory dynamics suggest that the reported effects of maternal exposure to hurricane destruction on fetal death may be conservative.


Subject(s)
Cyclonic Storms , Disasters , Fetal Mortality , Maternal Exposure/adverse effects , Birth Rate , Female , Housing , Humans , Louisiana/epidemiology , Odds Ratio , Risk Factors
17.
Am J Public Health ; 104 Suppl 1: S166-74, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24354824

ABSTRACT

OBJECTIVES: We analyzed singleton births to determine the relationship between birth weight and altitude exposure. METHODS: We analyzed 715,213 singleton births across 74 counties from the western states of Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, and Washington from January 1, 2000, to December 31, 2000. Birth data were obtained from the Division of Vital Statistics, National Center for Health Statistics, for registered births. RESULTS: Regression analyses supported previous research by showing that a 1000-meter increase in maternal altitude exposure in pregnancy was associated with a 75.9-gram reduction in birth weight (95% confidence interval = -84.1, -67.6). Quantile regression models indicated significant and near-uniform depressant effects from altitude exposure across the conditional distribution of birth weight. Bivariate sample-selection models showed that a 1000-meter increase in altitude exposure, over and above baseline residential altitude, decreased birth weight by an additional 58.8 grams (95% confidence interval = -98.4, -19.2). CONCLUSIONS: Because of calculable health care-related costs associated with lower birth weight, our reported results might be of interest to clinicians practicing at higher altitudes.


Subject(s)
Altitude , Birth Weight , Maternal Exposure/adverse effects , Adolescent , Adult , Female , Humans , Least-Squares Analysis , Middle Aged , Pregnancy , Regression Analysis , United States/epidemiology , Young Adult
18.
Environ Int ; 60: 7-14, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23973618

ABSTRACT

Soil lead in urban neighborhoods is a known predictor of child blood lead levels. In this paper, we address the question where one ought to concentrate soil sample collection efforts to efficiently predict children at-risk for soil Pb exposure. Two extensive data sets are combined, including 5467 surface soil samples collected from 286 census tracts, and geo-referenced blood Pb data for 55,551 children in metropolitan New Orleans, USA. Random intercept least squares, random intercept logistic, and quantile regression results indicate that soils collected within 1m adjacent to residential streets most reliably predict child blood Pb outcomes in child blood Pb levels. Regression decomposition results show that residential street soils account for 39.7% of between-neighborhood explained variation, followed by busy street soils (21.97%), open space soils (20.25%), and home foundation soils (18.71%). Just as the age of housing stock is used as a statistical shortcut for child risk of exposure to lead-based paint, our results indicate that one can shortcut the characterization of child risk of exposure to neighborhood soil Pb by concentrating sampling efforts within 1m and adjacent to residential and busy streets, while significantly reducing the total costs of collection and analysis. This efficiency gain can help advance proactive upstream, preventive methods of environmental Pb discovery.


Subject(s)
Environmental Exposure/analysis , Environmental Monitoring/methods , Lead/analysis , Lead/blood , Models, Statistical , Soil Pollutants/analysis , Soil/classification , Child , Female , Housing , Humans , Least-Squares Analysis , Male , Residence Characteristics/classification , Residence Characteristics/statistics & numerical data , Soil/chemistry , United States , Urban Population/statistics & numerical data
19.
Environ Pollut ; 178: 447-54, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23643852

ABSTRACT

This study examines exposure risks associated with lead smelter emissions at children's public playgrounds in Port Pirie, South Australia. Lead and other metal values were measured in air, soil, surface dust and on pre- and post-play hand wipes. Playgrounds closest to the smelter were significantly more lead contaminated compared to those further away (t(27.545) = 3.76; p = .001). Port Pirie post-play hand wipes contained significantly higher lead loadings (maximum hand lead value of 49,432 µg/m(2)) than pre-play hand wipes (t(27) = 3.57, p = .001). A 1% increase in air lead (µg/m(3)) was related to a 0.713% increase in lead dust on play surfaces (95% CI, 0.253-1.174), and a 0.612% increase in post-play wipe lead (95% CI, 0.257-0.970). Contaminated dust from smelter emissions is determined as the source and cause of childhood lead poisoning at a rate of approximately one child every third day.


Subject(s)
Air Pollutants/analysis , Environmental Exposure/analysis , Lead/analysis , Soil Pollutants/analysis , Child , Child Care , Environmental Exposure/statistics & numerical data , Environmental Pollution/statistics & numerical data , Humans , Lead Poisoning/epidemiology , Metallurgy , Play and Playthings , Risk Assessment , South Australia
20.
Environ Sci Technol ; 47(6): 2839-45, 2013 Mar 19.
Article in English | MEDLINE | ID: mdl-23428083

ABSTRACT

This study evaluates atmospheric concentrations of soil and Pb aerosols, and blood lead levels (BLLs) in 367839 children (ages 0-10) in Detroit, Michigan from 2001 to 2009 to test a hypothesized soil → air dust → child pathway of contemporary Pb risk. Atmospheric soil and Pb show near-identical seasonal properties that match seasonal variation in children's BLLs. Resuspended soil appears to be a significant underlying source of atmospheric Pb. A 1% increase in the amount of resuspended soil results in a 0.39% increase in the concentration of Pb in the atmosphere (95% CI, 0.28 to 0.50%). In turn, atmospheric Pb significantly explains age-dependent variation in child BLLs. Other things held equal, a change of 0.0069 µg/m(3) in atmospheric Pb increases BLL of a child 1 year of age by 10%, while approximately 3 times the concentration of Pb in air (0.023 µg/m(3)) is required to induce the same increase in BLL of a child 7 years of age. Similarly, a 0.0069 µg/m(3) change in air Pb increases the odds of a child <1 year of age having a BLL ≥ 5 µg/dL by a multiplicative factor of 1.32 (95% CI, 1.26 to 1.37). Overall, the resuspension of Pb contaminated soil explains observed seasonal variation in child BLLs.


Subject(s)
Air Pollutants/analysis , Lead/analysis , Lead/blood , Soil Pollutants/analysis , Aerosols/analysis , Atmosphere/analysis , Child , Child, Preschool , Environmental Exposure , Female , Humans , Infant , Infant, Newborn , Male , Michigan , Seasons
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