Blood Lead Levels in Children and Environmental Lead Contamination in Miami Inner City, Florida

Studies have shown that the environmental conditions of the home are important predictors of health, especially in low-income communities. Understanding the relationship between the environment and health is crucial in the management of certain diseases. One health outcome related to the home environment among urban, minority, and low-income children is childhood lead poisoning. The most common sources of lead exposure for children are lead paint in older, dilapidated housing and contaminated dust and soil produced by accumulated residue of leaded gasoline. Blood lead levels (BLL) as low as 10 μg/dL in children are associated with impaired cognitive function, behavior difficulties, and reduced intelligence. Recently, it is suggested that the standard for intervention be lowered to BLL of 5 μg /dl. The objectives of our report were to assess the prevalence of lead poisoning among children under six years of age and to quantify and test the correlations between BLL in children and lead exposure levels in their environment. This cross-sectional analysis was restricted to 75 children under six years of age who lived in 6 zip code areas of inner city Miami. These locations exhibited unacceptably high levels of lead dust and soil in areas where children live and play. Using the 5 μg/dL as the cutoff point, the prevalence of lead poisoning among the study sample was 13.33%. The study revealed that lead levels in floor dust and window sill samples were positively and significantly correlated with BLL among children (p < 0.05). However, the correlations between BLL and the soil, air, and water samples were not significant. Based on this pilot study, a more comprehensive environmental study in surrounding inner city areas is warranted. Parental education on proper housecleaning techniques may also benefit those living in the high lead-exposed communities of inner city Miami.

The effects of a family-based educational intervention on the prevention of lead poisoning in children

The effects of lead exposure may endure through one's lifetime and can negatively effect educational performance. While the link between the cause and effects of lead poisoning has been identified, the application of lead health education as the mechanism of disease prevention has not. The purpose of this study was to examine whether caregiver participation in a family-based educational intervention can result in decreased lead exposure in low socioeconomic children. ^ Participants (n = 50) were caregivers of children 12 to 36 months of age. They were randomly selected from an urban clinic and randomly assigned to either a treatment or control group. The experimental design of this study involved two clinic visits. Parents in the treatment group were given the educational intervention during the first clinic visit while those in the control group were given the intervention during the second clinic visit. The intervention was reinforced with a lead education brochure coupled with a video on childhood lead poisoning. One instrument was used to test parental knowledge of lead poisoning both pre- and post-intervention. Blood lead levels in pediatric participants were tested using two blood lead screens approximately three to four months apart determined by well-child check-up schedules. ^ Findings from the analysis of variance showed the interaction between the change in blood lead level between the children's first and second clinic visits and the treatment level. This demonstrated a significant interaction between the differences of first and second clinic visits blood lead levels and the presence or absence of the educational intervention. ^ The findings from an analysis of covariance support that caregivers in the treatment group have significantly higher scores on the second clinic visit scores on the CLKT than the caregivers in the control group. These data suggest that the educational treatment is effective in increasing the knowledge of caregivers about the dangers of lead poisoning and the strategies for lead poisoning prevention. ^ Conclusions indicate that the education of adult caregivers can affect blood lead levels of children, the educational treatment increased the knowledge of caregivers, caregivers were able to carry out procedures taught, and caregivers retained knowledge over time. ^

Development of risk based treatability and engineering measures for reducing exposure to lead contaminated media in the Miami inner city, Florida

A major consequence of contamination at the local level’s population as it relates to environmental health and environmental engineering is childhood lead poisoning. Environmental contamination is one of the pressing environmental concerns facing the world today. Current approaches often focus on large contaminated industrial size sites that are designated by regulatory agencies for site remediation. Prior to this study, there were no known published studies conducted at the local and smaller scale, such as neighborhoods, where often much of the contamination is present to remediate. An environmental health study of local lead-poisoning data in Liberty City, Little Haiti and eastern Little Havana in Miami-Dade County, Florida accounted for a disproportionately high number of the county’s reported childhood lead poisoning cases. An engineering system was developed and designed for a comprehensive risk management methodology that is distinctively applicable to the geographical and environmental conditions of Miami-Dade County, Florida. Furthermore, a scientific approach for interpreting environmental health concerns, while involving detailed environmental engineering control measures and methods for site remediation in contained media was developed for implementation. Test samples were obtained from residents and sites in those specific communities in Miami-Dade County, Florida (Gasana and Chamorro 2002). Currently lead does not have an Oral Assessment, Inhalation Assessment, and Oral Slope Factor; variables that are required to run a quantitative risk assessment. However, various institutional controls from federal agencies’ standards and regulation for contaminated lead in media yield adequate maximum concentration limits (MCLs). For this study an MCL of .0015 (mg/L) was used. A risk management approach concerning contaminated media involving lead demonstrates that the linkage of environmental health and environmental engineering can yield a feasible solution.

An Analysis of the Potential Risk Exposure to Lead (Pb) through Urban Community Gardens

Community gardening in cities is increasing, driven by social interaction and food security. City soils are sinks for heavy metals; including neurotoxic lead (Pb). Exposure routes are primarily through inhalation/ingestion of soil, or second by ingestion of plants that have accumulated Pb. This research evaluates soil at three Liberty City, Florida sites estimating risk of Pb exposure through primary and secondary pathways. Soil cores were collected from Liberty City, and red Malabar spinach (Basella rubra) was grown in Pb soil treatments in a greenhouse. Total soil Pb levels and plant tissues were measured after acid digestion, by ICP-OES. In Liberty City, two sites had hotspots with areas of elevated soil Pb levels. Plants grown on Pb contaminated soil all accumulated statistically significant Pb concentrations. Therefore, there is a potential risk of Pb exposure to residents in Liberty City by exposure in hotspot sites through both the primary and secondary pathways.

The impact of increased writing time allotment on the developmental writing skills of intermediate elementary school students

The purpose of this study is to determine which of several treatment groups and/or grades have shown growth when increased writing time allotment has occurred. Third, fourth and fifth grade students identified as Gifted, Learning Disabled, and Limited English Proficient enrolled in ESOL classes were the 69 subjects.^ All students were allotted at least one hour of writing time, four days a week for the school year of 1994-1995. Writing activities conducted during the school year involved the full writing process, including prewriting, drafting, revising, and editing. Pretests and posttests were administered across the grade levels at a designated period of time using the same administration procedures as the Florida Writing Assessment Program. Three teachers rated each sample on a scale of zero to three.^ The results of the oneway ANOVA indicated that the three raters did not score the pretests and posttests significantly different from each other. A single group pretest-posttest experimental design was used on the three groups. The results of the Gifted group revealed that the Gifted C subgroup (Gifted Behavioral) appeared to have averaged a higher gain score than both the Gifted A and Gifted B subgroups. For the four subgroups of the LD group, no distinct pattern was evident. The Group C subgroup (ADD) appeared to have scored lower than the other three subgroup although their mean IQ score was higher than the others LD subgroups. Comparisons were difficult to make among the four ESOL subgroups due to low subjects and/or scores. Qualitative analyses were also conducted using semi-structured interviews with the Gifted, Learning Disabled, and ESOL teachers. All believed the additional instructional time spent on writing made the difference in the increased writing scores.^ The study indicated that time alone is not a significant factor in developing accomplished writers. Direct instruction perhaps in a specific strategy or skill may lead to significant results. ^

Does hope matter? The influence of dispositional hope on persistence in a developmental writing course

The purpose of this study was to determine hope’s unique role, if any, in predicting persistence in a developmental writing course. Perceived academic self-efficacy was also included as a variable of interest for comparison because self-efficacy has been more widely studied than hope in terms of its non-cognitive role in predicting academic outcomes. A significant body of research indicates that self-efficacy influences academic motivation to persist and academic performance. Hope, however, is an emerging psychological construct in the study of non-cognitive factors that influence college outcomes and warrants further exploration in higher education. This study examined the predictive value of hope and self-efficacy on persistence in a developmental writing course. The research sample was obtained from a community college in the southeastern United States. Participants were 238 students enrolled in developmental writing courses during their first year of college. Participants were given a questionnaire that included measures for perceived academic self-efficacy and hope. The self-efficacy scale asked participants to self-report on their beliefs about how they cope with different academic tasks in order to be successful. The hope scale asked students to self-report on their beliefs about their capability to initiate action towards a goal (“agency”) and create a plan to attain these goals (“pathways”). This study utilized a correlational research design. A statistical association was estimated between hope and self-efficacy as well as the unique variance contributed by each on course persistence. Correlational analysis confirmed a significant relationship between hope and perceived academic self-efficacy, and a Fisher’s z-transformation confirmed a stronger relationship between the agency component of hope and perceived academic self-efficacy than for the pathways component. A series of multinomial logistic regression analyses were conducted to assess if (a) perceived self-efficacy and hope predict course persistence, (b) hope independent of self-efficacy predicts course persistence, and (c) if including the interaction of perceived self-efficacy and hope predicts course persistence. It was found that hope was only significant independent of self-efficacy. Some implications for future research are drawn for those who lead and coordinate academic support initiatives in student and academic affairs.

Prenatal environmental exposure and neurodevelopmentally important gene expression in malformed brain tissue from pediatric intractable epilepsy patients

The primary objective of this proposal was to determine whether mitochondrial oxidative stress and variation in a particular mtDNA lineage contribute to the risk of developing cortical dysplasia and are potential contributing factors in epileptogenesis in children. The occurrence of epilepsy in children is highly associated with malformations of cortical development (MCD). It appears that MCD might arise from developmental errors due to environmental exposures in combination with inherited variation in response to environmental exposures and mitochondrial function. Therefore, it is postulated that variation in a particular mtDNA lineage of children contributes to the effects of mitochondrial DNA damage on MCD phenotype. Quantitative PCR and dot blot were used to examine mitochondrial oxidative damage and single nucleotide polymorphism (SNP) in the mitochondrial genome in brain tissue from 48 pediatric intractable epilepsy patients from Miami Children’s Hospital and 11 control samples from NICHD Brain and Tissue Bank for Developmental Disorders. Epilepsy patients showed higher mtDNA copy number compared to normal health subjects (controls). Oxidative mtDNA damage was lower in non-neoplastic but higher in neoplastic epilepsy patients compared to controls. There was a trend of lower mtDNA oxidative damage in the non-neoplastic (MCD) patients compared to controls, yet, the reverse was observed in neoplastic (MCD and Non-MCD) epilepsy patients. The presence of mtDNA SNP and haplogroups did not show any statistically significant relationships with epilepsy phenotypes. However, SNPs G9804A and G9952A were found in higher frequencies in epilepsy samples. Logistic regression analysis showed no relationship between mtDNA oxidative stress, mtDNA copy number, mitochondrial haplogroups and SNP variations with epilepsy in pediatric patients. The levels of mtDNA copy number and oxidative mtDNA damage and the SNPs G9952A and T10010C predicted neoplastic epilepsy, however, this was not significant due to a small sample size of pediatric subjects. Findings of this study indicate that an increase in mtDNA content may be compensatory mechanisms for defective mitochondria in intractable epilepsy and brain tumor. Further validation of these findings related to mitochondrial genotypes and mitochondrial dysfunction in pediatric epilepsy and MCD may lay the ground for the development of new therapies and prevention strategies during embryogenesis.

Reliability analysis of encapsulation methods for lead -based paint through an accelerated life testing

The adverse health effects of long-term exposure to lead are well established, with major uptake into the human body occurring mainly through oral ingestion by young children. Lead-based paint was frequently used in homes built before 1978, particularly in inner-city areas. Minority populations experience the effects of lead poisoning disproportionately. ^ Lead-based paint abatement is costly. In the United States, residents of about 400,000 homes, occupied by 900,000 young children, lack the means to correct lead-based paint hazards. The magnitude of this problem demands research on affordable methods of hazard control. One method is encapsulation, defined as any covering or coating that acts as a permanent barrier between the lead-based paint surface and the environment. ^ Two encapsulants were tested for reliability and effective life span through an accelerated lifetime experiment that applied stresses exceeding those encountered under normal use conditions. The resulting time-to-failure data were used to extrapolate the failure time under conditions of normal use. Statistical analysis and models of the test data allow forecasting of long-term reliability relative to the 20-year encapsulation requirement. Typical housing material specimens simulating walls and doors coated with lead-based paint were overstressed before encapsulation. A second, un-aged set was also tested. Specimens were monitored after the stress test with a surface chemical testing pad to identify the presence of lead breaking through the encapsulant. ^ Graphical analysis proposed by Shapiro and Meeker and the general log-linear model developed by Cox were used to obtain results. Findings for the 80% reliability time to failure varied, with close to 21 years of life under normal use conditions for encapsulant A. The application of product A on the aged gypsum and aged wood substrates yielded slightly lower times. Encapsulant B had an 80% reliable life of 19.78 years. ^ This study reveals that encapsulation technologies can offer safe and effective control of lead-based paint hazards and may be less expensive than other options. The U.S. Department of Health and Human Services and the CDC are committed to eliminating childhood lead poisoning by 2010. This ambitious target is feasible, provided there is an efficient application of innovative technology, a goal to which this study aims to contribute. ^

Does Hope Matter? The Influence of Dispositional Hope on Persistence in a Developmental Writing Course

The purpose of this study was to determine hope’s unique role, if any, in predicting persistence in a developmental writing course. Perceived academic self-efficacy was also included as a variable of interest for comparison because self-efficacy has been more widely studied than hope in terms of its non-cognitive role in predicting academic outcomes. A significant body of research indicates that self-efficacy influences academic motivation to persist and academic performance. Hope, however, is an emerging psychological construct in the study of non-cognitive factors that influence college outcomes and warrants further exploration in higher education. This study examined the predictive value of hope and self-efficacy on persistence in a developmental writing course. The research sample was obtained from a community college in the southeastern United States. Participants were 238 students enrolled in developmental writing courses during their first year of college. Participants were given a questionnaire that included measures for perceived academic self-efficacy and hope. The self-efficacy scale asked participants to self-report on their beliefs about how they cope with different academic tasks in order to be successful. The hope scale asked students to self-report on their beliefs about their capability to initiate action towards a goal (“agency”) and create a plan to attain these goals (“pathways”). This study utilized a correlational research design. A statistical association was estimated between hope and self-efficacy as well as the unique variance contributed by each on course persistence. Correlational analysis confirmed a significant relationship between hope and perceived academic self-efficacy, and a Fisher’s z-transformation confirmed a stronger relationship between the agency component of hope and perceived academic self-efficacy than for the pathways component. A series of multinomial logistic regression analyses were conducted to assess if (a) perceived self-efficacy and hope predict course persistence, (b) hope independent of self-efficacy predicts course persistence, and (c) if including the interaction of perceived self-efficacy and hope predicts course persistence. It was found that hope was only significant independent of self-efficacy. Some implications for future research are drawn for those who lead and coordinate academic support initiatives in student and academic affairs.

Effects of Prenatal and Early Postnatal Exposure to Aversive Stimuli on Fearfulness and Exploratory Behavior in Bobwhite Qauil Neonates (Colinus virginianus)

Neophobia, the fear of novelty, is a behavioral trait found across a number of animal species, including humans. Neophobic individuals perceive novel environments and stimuli to have aversive properties, and exhibit fearful behaviors when presented with non-familiar situations. The present study examined how early life exposure to aversive novel stimuli could reduce neophobia in bobwhite quail chicks. Experiment 1 exposed chicks to a novel auditory tone previously shown to be aversive to naïve chicks (Suarez, 2012) for 24 hours immediately after hatching, then subsequently tested them in the presence of the tone within a novel maze task. Postnatally exposed chicks demonstrated decreased fearfulness compared to naïve chicks, and behaved more similarly to chicks tested in the presence of a known attractive auditory stimulus (a bobwhite maternal assembly call vocalization). Experiment 2 exposed chicks to the novel auditory tone for 24 hours prenatally, then subsequently tested them within a novel maze task. Prenatally exposed chicks showed decreased fearfulness to a similar degree as those postnatally exposed, revealing that both prenatal and postnatal exposure methods are capable of decreasing fear of auditory stimuli. Experiment 3 exposed chicks to a novel visual stimulus for 24 hours postnatally, then subsequently tested them within a novel emergence box / T-maze apparatus. Chicks exposed to the visual stimulus showed decreased fearfulness compared to naïve chicks, thereby demonstrating the utility of this method across sense modalities. Experiment 4 assessed whether early postnatal exposure to one novel stimulus could generalize and serve to decrease fear of novelty when chicks were tested in the presence of markedly different stimuli. By combining the methods of Experiments 1 and 3, this experiment revealed that chicks exposed to one type of stimulus (auditory or visual) demonstrated decreased fear when subsequently tested in the presence of the opposite type of novel stimulus. These results suggest that experience with novel stimuli can moderate the extent to which neophobia will develop during early development.