Sources of lead exposure in various countries

This review evaluates the sources of lead exposure worldwide. Studies from searches relating to sources of lead exposure in various countries within different regional zones were reviewed. Results indicated that in Nigeria, exposure sources include electronic waste, paint and batteries. In Mexico exposure sources include glazed ceramics, lead contaminated utensils and lead contaminated water, for India lead sources include cosmetics and traditional medicines. Sources of lead exposure in China include e-waste, traditional medicines and industrial emissions. In France, exposure sources included lead paint from older homes, imported ceramics and cosmetics and industrial emissions. Australia's exposure sources include paint, dust, imported toys and traditional medicines. Finally, in the United States exposure sources included paint, the industrial legacy of lead exposure and batteries. In high-income countries (HICs) the legacy of lead exposure keeps populations continuously exposed. In lower- and middle-income countries (LMICs), in addition to the legacy of lead exposure, lack of regulations or the inability to enforce regulations keeps populations exposed. In all, evidence suggests that lead exposure remains an issue of public health significance in both HIC and LMIC.

Cardiovascular-Related Outcomes in U.S. Adults Exposed to Lead

Cardiovascular-related clinical markers were evaluated in this cross-sectional study of United States adults (aged ≥ 20) exposed to lead via the National Health and Nutrition Examination Survey 2007-2008 and the 2009-2010 datasets. In four quartiles of exposure-0-2 μg/dL, 2-5 μg/dL, 5-10 μg/dL, and 10 μg/dL and over, clinical and anthropometric markers were evaluated-to examine how the markers manifested in the quartiles. Associations were determined via linear regression. Finally, clinical makers, and how they manifested between exposed and less-exposed occupations, were explored in addition to how duration of exposure altered these clinical markers. In regression analysis, Diastolic Blood Pressure (DBP) and high-density lipoprotein (HDL) cholesterol, were significantly associated with blood lead level (BLL). In the occupational analysis, Systolic Blood Pressure (SBP), DBP, C-reactive protein (CRP), triglycerides, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, showed differences between populations in the exposed and less-exposed occupations. Regarding Agriculture, Forestry & Fishing, the duration of exposure altered SBP, CRP, and LDL cholesterol. With mining, the duration of exposure altered SBP, DBP, triglycerides, and HDL cholesterol, whereas in construction, the duration in occupation altered SBP, triglycerides, and CRP. In conclusion, lead exposure has a profound effect on the cardiovascular system, with potentially adverse outcomes existing at all exposure levels.

Chronic cadmium exposure and cardiovascular disease in adults

Chronic cadmium exposure and its effect on cardiovascular-related markers were explored in the cross-sectional study of U.S. adults using the National Health and Nutrition Examination Survey (NHANES) 2007-2010 data. Cardiovascular-related markers, such as LDL cholesterol mg/dL (LDL-C), non-HDL cholesterol mg/dL (non-HDL-C), triglycerides mg/dL (TG), c-reactive protein mg/dL (CRP), and gamma-glutamyl transferase U/L (GGT) were explored in relation to urine cadmium level µg/L (UCL). The variables and their relation to UCL µg/L were explored both as continuous and categorical variables using linear and logistic regression models and basic descriptive statistics. Geometric Mean values of the markers of interest were statistically significantly more elevated in middle-aged adults (45-65 years) as compared to younger adults (18-44 years). In linear regression analysis, CRP mg/dL, LDL-C mg/dL, non-HDL-C mg/dL, and GGT U/L levels were significantly associated with UCLs mg/dL after adjusting for confounding variables. In binary logistic regression models, young and middle-aged adults chronically exposed to cadmium were significantly more likely to have elevated CRP mg/dL levels. This study suggests that chronic exposure to cadmium alters cardiovascular-related markers in middle-aged adults more so than younger adults, which calls for early public health intervention to limit cadmium exposure in the U.S.

Lead Distribution in Urban Soil in a Medium-Sized City: Household-Scale Analysis

This study characterizes potential soil lead (Pb) exposure risk at the household scale in Greensboro, North Carolina, using an innovative combination of field sampling, statistical analysis, and machine-learning techniques. Soil samples were collected at the dripline, yard, and street side at 462 households (total sample size = 2310). Samples were analyzed for Pb and then combined with publicly available data on potential historic Pb sources, soil properties, and household and neighborhood demographic characteristics. This curated data set was then analyzed with statistical and machine-learning techniques to identify the drivers of potential soil Pb exposure risks and to build predictive models. Among all samples, 43% exceeded current guidelines for Pb in residential gardens. There were significant racial disparities in potential soil Pb exposure risk; soil Pb at the dripline increased by 19% for every 25% increase in the neighborhood population identifying as Black. A machine-learned Bayesian network model was able to classify residential parcels by risk of exceeding residential gardening standards with excellent reproducibility in cross validation. These findings underscore the need for targeted outreach programs to prevent Pb exposure in residential areas and demonstrate an approach for prioritizing outreach locations.

Combined Effect of Lead Exposure and Allostatic Load on Cardiovascular Disease Mortality-A Preliminary Study

This study explores the combined effect of lead (Pb) exposure and an index of chronic physiological stress on cardiovascular disease mortality using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2008 linked to 1999-2014 National Death Index data. Chronic physiological stress was measured using the allostatic load (AL) index, which was formed by analyzing markers from the cardiovascular, inflammatory, and metabolic systems, with Pb levels, assessed using blood lead levels (BLL). The dataset was analyzed with statistical techniques to explore (a) the relationship between Pb exposure and AL, and (b) the combined role of Pb and AL on cardiovascular disease mortality. Results indicated that AL was more elevated in those with BLLs above the 50th percentile in the US population and that those with elevated AL were more likely to have high BLL. Finally, the interaction of AL and BLL significantly increased the likelihood of cardiovascular disease mortality. These findings highlight the need for considering the totality of exposures experienced by populations to build holistic programs to prevent Pb exposure and reduce stressors to promote optimal health outcomes and reduce cardiovascular mortality risk.

Lead Exposure and Cardiovascular Disease among Young and Middle-Aged Adults

Lead and its effects on cardiovascular-related markers were explored in this cross-sectional study of young adults (18–44 years) and middle-aged adults (45–65 years) from the United States using the National Health and Nutrition Examination Survey (NHANES), 2009–2016. Degrees of exposure were created using blood lead level (BLL) as the biomarker of exposure based on the epidemiologically relevant threshold of BLL > 5 μg/dL. The mean values, in addition to the percentages of people represented for the markers of interest (systolic blood pressure [SBP], diastolic blood pressure [DBP], gamma-glutamyl transferase [GGT], non-high-density lipoprotein cholesterol [non-HDL-C]) were explored. Among those exposed to lead, the likelihood of elevated clinical markers (as defined by clinically relevant thresholds of above normal) were examined using binary logistic regression. In exploring exposure at the 5 μg/dL levels, there were significant differences in all the mean variables of interest between young and middle-aged adults. The binary logistic regression showed young and middle-aged adults exposed to lead were significantly more likely to have elevated markers (apart from DBP). In all, lead affects cardiovascular-related markers in young and middle-aged U.S. adults and thus we must continue to monitor lead exposure to promote health.

The Association between Multiple Per- and Polyfluoroalkyl Substances' Serum Levels and Allostatic Load

Background/Objective: This study aimed to explore the association between allostatic load (AL), an index of chronic stress, with nine per- and polyfluoroalkyl substances (PFASs), a group of organic compounds used in commercial and industrial applications. The PFASs explored were perfluorohexane sulfonic acid (PFHS), perfluorodecanoic acid (PFDE), perfluorobutane sulfonic acid (PFBS), perfluoroheptanoic acid (PFHP), perflurododecanoic acid (PFDO), perfluorononanoic acid (PFNA), perfluoroundecanoic acid (PFUA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS). This study was performed to better understand the association between PFASs and AL, which may be a mediator of several diseases. Methods: This study was performed on adults aged 20 and older, using the National Health and Nutrition Examination Survey (NHANES) 2007−2014 data. AL was calculated as a cumulative index of ten biomarkers from the cardiovascular, inflammatory, and metabolic system, which was dichotomized into high risk (assigned a value of 1) or low risk (assigned a value 0) depending on if the index value was ≥3 (chronic physiological stress) or <3 (less stressed). In this study, PFASs and covariates such as age, gender, ethnicity, alcohol consumption, smoking, and physical activity were explored using descriptive statistics and logistic regression modeling. Results: The results indicated that in adults, AL was more elevated in men as compared to women, in those aged ≥60 years, and varied by ethnicity. For instance, non-Hispanic Blacks had higher AL levels (mean of 3.92) compared to other ethnicities. A significant number of the participants tested for PFBS, PFHP, PFDO were below the LOD and thus these PFASs were excluded from the analysis. Our analysis demonstrated multicollinearities between variables such as PFNA, PFOS, and PFOA with variance inflation factor (VIF) values of 6.197, 6.212, and 5.139, respectively. Thus, PFASs were analyzed individually and adjusted for age, gender, ethnicity, physical activity, smoking, and alcohol consumption. The results indicated a statistically significant positive association between AL and most of the PFASs, except PFUA which was not statistically significant with a p value of 0.531. Conclusions: The findings of this study suggest that exposure to PFDE, PFNA, PFOS, PFOA, and PFHS are associated with AL when adjusted for age, gender, ethnicity, alcohol consumption, smoking, and physical activity. Future studies looking to model the effects of these factors together must consider their relationship with each other and choose different analytical approaches.

Blood Pressure and Oxidative Stress among U.S. Adults Exposed to Lead in Military Environments-A Preliminary Study

In this cross-sectional study, lead exposure among those with a history in military environments was examined. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) are clinical markers of blood pressure, while gamma-glutamyl transferase (GGT) is a marker of oxidative stress. These markers and their effects on those exposed to military environments were explored using National Health and Nutrition Examination Survey (NHANES) data from 2009 to 2016. Mean SBP and GGT were significantly elevated in those exposed to military environments, with a moderately significant association existing between blood lead levels (BLLs) and SBP. More attention must be given to lead exposure in military environments to mitigate the risk of exposure.

Elevated blood lead and metal/metalloid levels and environmental exposure sources in urban Ecuadorian school-age children and mothers

BACKGROUND

Lead and other toxic and potentially toxic metals and metalloids are significant contributors to the global burden of disease and disability. Studies characterizing blood metal/metalloid levels and potential sources of environmental exposures are limited for populations living in the major urban centers of Andean-area countries.

METHODS

We used ICP-MS to quantify blood levels of lead (PbB), cadmium (CdB), manganese (MnB), total arsenic (AsB), and total mercury (HgB) in school-age children (n = 47) and their reproductive-age mothers (n = 49) from low-resource households in Quito, Ecuador. These were compared to published 95th percentile reference values (RV95) and for PbB, also to CDC reference values. We used a detailed environmental questionnaire to examine the contribution of residential and neighborhood environmental exposure sources with participant blood metal/metalloid levels. We used ICP-MS to measure Pb levels in residential windowsill dust, floor dust, and drinking water samples and used XRF for paint samples.

RESULTS

Forty-five percent of the mothers had PbBs ≥ 5 μg/dL; 14.3% had PbBs ≥10 μg/dL. Maternal blood levels exceeded RV95s for PbB (76%), CdB (41%), MnB (88%), HgB (57%), and AsB (90%). Of children, 68% had PbBs ≥ 5 μg/dL, and 21.3% had PbB ≥10 μg/dL. Most child blood levels exceeded the RV95s for PbB (100%), CdB (100%), MnB (94%), and total HgB (94%) and AsB (98%). Most mothers (97%) and all children had blood levels indicating exposure to multiple metal/metalloid mixtures. Maternal and child PbBs were moderately correlated with each other but the other four metals/metalloids were not. Factors associated with maternal blood metal/metalloid levels were residence in a home with an earthen floor (PbB) or bare cement block walls (MnB), living near a dirt-paved or cobblestone street (PbB), <50 m from a heavily trafficked major roadway (PbB, HgB), living in the Los Chillos (PbB) or Cotocollao neighborhoods (PbB, HgB), or in areas where street vendors grilled food using charcoal (MnB). Factors associated with child blood metal/metalloid levels were residence in a dirt floor home (PbB, CdB, AsB), living near a dirt-paved or cobblestone street (PbB), living in the El Camal or Cotocollao neighborhoods (AsB), or in local neighborhoods where scrap metal smelters (MnB) and LPG gas depositories (PbB) were present.

CONCLUSIONS

The elevated blood levels of PbB, other metal/metalloids, and metal/metalloid mixtures identified mothers and children in this exploratory study is an urgent public health and clinical concern. The exposure patterns suggest that traffic-related exposures, especially the resuspension of legacy Pb in dust, as well as other anthropogenic and geogenic sources may be important environmental contributors to metal/metalloid exposures in urban Ecuadorian mothers and children. Future studies are needed to confirm these findings and explore other potential exposure sources. Biomonitoring is also needed in order to formulate effective intervention strategies to reduce population exposure to toxic levels of environmental metals/metalloids.

The Association of Toxoplasma gondii IgG and Cardiovascular Biomarkers

Background: Toxoplasma gondii (T. gondii) is a protozoan parasite with high prevalence worldwide. More than 40 million individuals in the United States carry this parasite. T. gondii infection causes toxoplasmosis, which is the leading cause of death associated with foodborne diseases in the United States. T. gondii infects humans through different routes, and it is capable of invading a wide range of tissues in the human body following the infection. Methods: The main objective of this study was to investigate the prevalence of T. gondii among adults in the United States and its association with cardiovascular health using data from the National Health and Nutrition Examination Survey (NHANES 2009-2010). Considering the limitation of studies investigating the relationship between T. gondii and cardiovascular biomarkers, this study was focused on assessing the association of T. gondii to nine cardiovascular biomarkers. First, those biomarkers were investigated individually using several statistical tests and models. Second, we developed an overall cardiovascular biomarker index (OCBI) from eight critical biomarkers to better explain the T. gondii potential cumulative effect on the cardiovascular system. These analyses were adjusted for demographic, behavioral, and anthropometric factors. Results:T. gondii IgG antibody-positive participants had significantly higher systolic blood pressure (p = 0.0022), triglycerides (p = 0.0399), C-reactive protein (p = 0.0422), gamma glutamyl transferase (p = 0.0400), and fasting glucose (p = 0.0213) than the negative participants. In addition, the positive participants had significantly lower high-density lipoprotein cholesterol (p = 0.0431) than the negative participants. Adjusting for age, T. gondii positive had a significant negative association with high-density lipoprotein cholesterol (p = 0.0026) and a significant positive association with low-density lipoprotein cholesterol (p = 0.0179), triglycerides (p = 0.0154), and gamma glutamyl transferase (p = 0.0026). With the exception of the low-density lipoprotein, these associations remained statistically significant when adjusting for demographic, behavioral, and anthropometric factors. These results potentially indicate the role of T. gondii in driving cardiovascular-related biomarkers toward dysfunction. The analysis also revealed a significant difference in the OCBI among positive and negative participants (p = 0.0020), with the (cumulative) odds of positive participants having a higher level of OCBI being 0.71 times lower than the odds for negative participants (OR = 0.29). Conclusions: Positive T. gondii IgG antibody was significantly associated with adverse effects on cardiovascular-related biomarkers, including systolic blood pressure, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and gamma glutamyl transferase. T. gondii-positive individuals were more likely to have a lower cardiovascular biomarkers index than the negative individuals. Finally, the prevalence of toxoplasmosis among U.S. adults was associated with demographic characteristics including age, ethnicity, country of birth, and occupation.

Cumulative Effects of Low-Level Lead Exposure and Chronic Physiological Stress on Hepatic Dysfunction-A Preliminary Study

Chronic physiological stress and hepatic injury were explored in this cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) 2007–2010. Lead exposure was measured using Blood Lead Levels (BLL), which were divided into quartiles of exposure based on the distribution within the database. Allostatic load (AL), a variable representing chronic physiological stress, was operationalized using ten clinical markers. The geometric mean values for markers of liver injury of interest (a) Aspartate Aminotransferase (AST), (b) Alanine Aminotransferase (ALT), (c) Alkaline Phosphatase (ALP), and (d) Gamma glutamyl-transferase (GGT) were explored in quartiles of lead exposure. Associations between AL and AST, ALT, ALP, and GGT among those exposed to lead were analyzed using linear regression models. In examining lead exposure in increasing quartiles, the geometric mean of the liver injury markers showed significant elevations as lead exposure levels increased. Simple linear regression revealed AL was positively associated with several markers of hepatic injury in all degrees of lead exposure. This study demonstrates the potential dangers of social and environmental exposures to liver health.

Association of Combined Metals and PFAS with Cardiovascular Disease Risk

This study sought to investigate the impact of exposure to metals and per- and polyfluoroalkyl substances (PFASs) on cardiovascular disease (CVD)-related risk. PFASs, including PFOA, PFOS, PFNA, and PFHxS, as well as metals such as lead (Pb), cadmium (Cd), and mercury (Hg), were analyzed to elucidate their combined effects on CVD risk.

METHODS

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2007 to 2014, this investigation explored the effects of PFASs and metals on CVD risk. A spectrum of individual CVD markers, encompassing systolic blood pressure (SBP), diastolic blood pressure (DBP), high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, and triglycerides, was examined. Additionally, comprehensive CVD risk indices were evaluated, namely the Overall Cardiovascular Biomarkers Index (OCBI), including the Framingham Risk Score and an Overall Cardiovascular Index. Linear regression analysis was employed to probe the relationships between these variables. Furthermore, to assess dose-response relationships between exposure mixtures and CVD while mitigating the influence of multicollinearity and potential interaction effects, Bayesian Kernel Machine Regression (BKMR) was employed.

RESULTS

Our findings indicated that exposure to PFAS and metals in combination increased CVD risk, with combinations occurring with lead bringing forth the largest impact among many CVD-related markers.

CONCLUSIONS

This study finds that combined exposure to metals and PFASs significantly elevates the likelihood of CVD risk. These results highlight the importance of understanding the complex interplay between multipollutant exposures and their potential implications for cardiovascular health.

The Association of Toxoplasma gondii IgG Antibody and Chronic Kidney Disease Biomarkers

BACKGROUND

Toxoplasma gondii (T. gondii) is a parasite that infects more than 40 million Americans and causes toxoplasmosis. Most cases of toxoplasmosis are asymptomatic; however, T. gondii is capable of invading organs like the kidney, causing chronic infections and cell destruction.

METHODS

This study focused on evaluating the association between T. gondii exposure and chronic kidney disease (CKD) using data from the 2009-2010 National Health and Nutrition Examination Survey (NHANES). T. gondii exposure was assessed using Toxoplasma gondii IgG antibody status, and the status of CKD was assessed using the CKD biomarkers. The evaluation of risk rate and population prevalence was performed. In addition, multivariable regression models were used to further investigate this association after adjusting for sociodemographic, anthropometric, behavioral, and clinical covariates commonly associated with kidney dysfunction.

RESULTS

The positive T. gondii IgG antibody participants had significantly higher levels of CKD biomarkers, including second albumin-to-creatinine ratio (p = 0.0376), second albuminuria (p = 0.0005), and persistent albuminuria (p < 0.0001) compared to the negative participants. Furthermore, there were statistical associations between T. gondii exposure and the status of CKD (negative vs. positive) (p = 0.0001), and between T. gondii exposure and the CKD stage (negative, stage 1, …, stage 5) (p = 0.0004). Without adjusting for age, the positive T. gondii participants had a significantly higher risk (27% higher) of having CKD than the negative participants (RRcrude = 1.27, 95% CI: 1.09-1.49). The age-adjusted prevalence of CKD was higher among Toxoplasma-positive participants compared to the Toxoplasma-negative participants (10.45 vs. 8.99). T. gondii infection was significantly associated with CKD (OR = 1.40, 95% CI = 1.06-1.84, p = 0.00447) after adjusting for age, gender, race/ethnicity, and BMI. Age was positively associated with CKD (OR = 8.89, 95% CI = 6.31-12.51, p < 0.0001) with the participants 45+ years old being 8.89 times more likely to have CKD than those who are <45 years old, after adjusting for T. gondii infection, gender, race/ethnicity, and BMI. Moreover, positive T. gondii increased the odds of CKD progression (OR = 1.41, 95% CI = 1.07-1.86, p = 0.0424).

CONCLUSIONS

Positive T. gondii IgG antibody is associated with CKD and the progression of CKD stages. This association is more apparent among older people. Further investigations are needed to examine these findings in different geographical locations and among differentially exposed populations.

Teachers' Strategies in Combating Diseases in Preschools' Environments

Scholarship on child health indicates that the early years of life are vital for all aspects of health and development. In particular, a solid health foundation predicts good life outcomes; therefore, systematic strategies for combating diseases are needed to ensure optimal health of young children in early care environments. This study examined strategies used by 48 preschool teachers from 10 pre-schools in the US Midwest in order to combat diseases. The following results emerged: Participants noted that children should not attend childcare if they are vomiting, have a fever or have diarrhea. They should be symptom-free for at least one day before returning to school. It is recommended that children be sent home if they have any disease deemed to have adverse effects on their health during the school day. Participants noted further that children must not share hats in their childcare environments to avoid transfer of head lice. Since no strategies were mentioned to help children cope with emotional distress and illness, it is recommended that teachers develop strategies that will address emotional childhood diseases in order to help all children.

Women's perspectives on human milk banking in Ghana: results from a cross-sectional study

Background

Although political and academic interest exists in Ghana to include human milk banks (HMB) into current maternal and child health programs, efforts to establish a HMB have not yet been subjected to any real empirical inspection with the view toward implementation. Furthermore, views toward the establishment of a HMB in Ghana have not been assessed among Ghanaian women. The aims of the current study were to examine Ghanaian women's views about HMB, and to investigate women's willingness to donate to a HMB.

Methods

Quantitative and qualitative responses were received from Ghanaian females (n = 1,270) aged 18+ years. Excluding outliers and missing data (n = 321), a final sample of 949 was retained for final analysis. Chi-square tests and logistic regression analysis were computed on quantitative data; Thematic analysis was performed on the qualitative responses.

Results

In our sample, 64.7% of respondents indicated that Ghana is ready for a HMB. The majority (77.2%) were willing to donate milk, and 69.4% believed that donating to the HMB would favor their child. The main concerns for the unwillingness to donate excess milk included: (i) the idea of HMBs as strange/bizarre (n = 47), (ii) fear of infections (n = 15), (iii) religious beliefs (n = 9), and (iv) insufficient information (n = 24). This study serves as the first step toward the development of a HMB in Ghana.

Conclusions

Overall, Ghanaian women support the building of a HMB to enhance infant nutrition and reduce childhood morbidity and mortality.

Interaction of Per- and Polyfluoroalkyl Substances and Allostatic Load among Adults in Various Occupations

Objective: This study sought to assess the associations between occupation, serum concentrations of selected of Per- and Polyfluoroalkyl Substances (PFAS), and chronic physiological stress, as operationalized by Allostatic Load (AL), among adults aged ≥20 years. Methods: To explore the interactions of occupation with PFAS levels and AL, data from the National Health and Nutrition Examination Survey (NHANES) 2007−2014 were used. We performed Poisson regression modeling to evaluate AL’s relationships with PFAS concentrations and occupations on weighted data. Results: The results demonstrated that increased AL was positively associated with different occupation groups such as a) Public Administration and b) Arts, Entertainment, and Recreation (p-values 0.018 and 0.002, respectively), and with certain PFAS concentrations (Perfluorooctanoic acid, PFOA, p-value = 0.002). Finally, AL had a strong association with the interaction of some PFAS such as Perfluorobutane sulfonic acid (PFBS) and occupation (AL: PFBS: occupation, p-value < 0.0001), with different association measures existing across varying occupations. Conclusions: Occupation and PFOA seem to be associated with AL. This suggests the need of implementing further strategies to limit the exposure to stressors and PFAS in the work environment to promote longevity among the workforce in the U.S. Finally, policymakers must do more to clearly define standards and regulations in the work environment related to PFAS exposure.

Association of Per- and Polyfluoroalkyl Substances with Allostatic Load Stratified by Herpes Simplex Virus 1 and 2 Exposure

Herpes Simplex Virus (HSV) 1 and 2 are persistent infections that affect a significant percentage of United States (US) adults, with 48% having HSV-1 and 12% having HSV-2. Using data stratified by HSV-1 and HSV-2 exposures, this study investigated the association of per- and polyfluoroalkyl substances (PFAS), a group of toxic synthetic organofluorine chemical compounds found in environmental, occupational, and home settings, with allostatic load (AL), an index of chronic physiological stress. Descriptive statistics, multivariable logistic regression, and Bayesian Kernel Machine Regression (BKMR) modeling were used to assess the effects of multi-PFAS exposures on AL using data from the National Health and Nutrition Examination Survey (NHANES) 2007-2014. Results indicated participants not exposed to PFAS exhibited 77% to 97% lower odds of higher AL (p < 0.001). For example, PFOS per unit increase brought forth a 2% odds increase in higher AL (OR: 1.02; 95% CI: 1.00, 1.05; p < 0.05). Participants exposed to PFAS had reduced odds of higher AL (77%-79%), regardless of their HSV-1 and HSV-2 status. PFAS exposure was more prevalent in those with HSV-1 (60%) than in those with HSV-2 (20%) infection, while AL levels were comparable in both groups (17%). BKMR revealed a nonlinear PFAS-AL association and confirmed interactions among PFAS. In summary, PFAS exposure increased the likelihood of higher AL among those with persistent HSV infections. Our study enhances the current understanding of the complex dynamics involving PFAS, persistent infections, and AL, which hold significant implications for public health and clinical intervention strategies.

Per- and Polyfluoroalkyl Substances: Toxic Chemicals of Concern in North Carolina

Per- and polyfluoroalkyl substances (PFASs), a family of human-made chemicals often described as "forever chemicals," are observed in a wide range of products utilized by North Carolinians and can cause liver damage, cancer, and infertility. Owing to their widespread use and persistence in the environment, humans and animals are exposed to individual and combinations of PFASs.

Soil-skin adherence measures from hand press trials in a Gulf study of exposures

Marine oil spills and the resulting environmental contamination is common along coastal areas; however, information is lacking about the safety of impacted beaches for public use, especially for the most vulnerable population: children. One route of exposure for children at oil impacted beaches is through contact with sands. The purpose of this study was to evaluate beach sand skin adherence for children under the age of seven. Each of 122 children participated in a hand press trial conducted at one of four different U.S. beaches (two in Miami, FL, and two in Galveston, TX USA). During the hand press trials, hand conditions of the children were randomized (dry, wet, or with sunscreen), and soil adherence (mass of sand per palmar surface area of the hand) and the maximum pressure applied (force applied per area of hand) was measured and calculated. Each child was instructed to press their hands on a soil laden tray for 5 s and pressure of contact was measured using a scale. Results (n = 98) showed that the average soil adherence for both palmar hands across the four beaches ranged from 0.200 to 234 mg/cm² with an average of 35.7 mg/cm², with boys (40.4 mg/cm²) showing slightly higher means than girls (31.7 mg/cm²), but these differences were not significant even after adjusting for age. Among the three conditions evaluated, the highest loading was measured for children with wet hands (mean 65.3 mg/cm²), followed by dry hands (mean 24.5 mg/cm²). Sunscreen hands (mean 23.2 mg/cm²) had the lowest loadings. The pressure of contact ranged from 0.180 to 1.69 psi and varied by age groups and by height and weight, where pressure of contact did not have a significant influence on soil adherence. The average adhered sand grain size and average ambient sand grain size both had a statistically significant impact on hand soil adherence. Overall results from this study can be utilized in exposure and risk assessment models to evaluate the possible health impacts from contaminants found in beach sands.

Combined Effects of Multiple Per- and Polyfluoroalkyl Substances Exposure on Allostatic Load Using Bayesian Kernel Machine Regression

This study aims to investigate the combined effects of per- and polyfluoroalkyl substances (PFAS) on allostatic load, an index of chronic stress that is linked to several chronic diseases, including cardiovascular disease and cancer. Using data from the National Health and Nutrition Examination Survey (NHANES) 2007-2014, this study examines the relationship between six PFAS variables (PFDE, PFNA, PFOS, PFUA, PFOA, and PFHS) and allostatic load using Bayesian Kernel Machine Regression (BKMR) analysis. The study also investigates the impact of individual and combined PFAS exposure on allostatic load using various exposure-response relationships, such as univariate, bivariate, or multivariate models. The analysis reveals that the combined exposure to PFDE, PFNA, and PFUA had the most significant positive trend with allostatic load when it was modeled as a binary variable, while PFDE, PFOS, and PFNA had the most significant positive trend with allostatic load when modeled as a continuous variable. These findings provide valuable insight into the consequences of cumulative exposure to multiple PFAS on allostatic load, which can help public health practitioners identify the dangers associated with potential combined exposure to select PFAS of interest. In summary, this study highlights the critical role of PFAS exposure in chronic stress-related diseases and emphasizes the need for effective strategies to minimize exposure to these chemicals to reduce the risk of chronic diseases. It underscores the importance of considering the combined effects of PFAS when assessing their impact on human health and offers valuable information for policymakers and regulators to develop strategies to protect public health.

The Association of Toxoplasma gondii IgG and Liver Injury in US Adults

BACKGROUND

Toxoplasma gondii (T. gondii) is a ubiquitous obligatory intracellular parasite which infects over 40 million Americans and causes toxoplasmosis. Inside the human body, T. gondii can damage tissues and invade vital organs.

METHODS

This study evaluated the association of T. gondii infection and liver disease using data from the National Health and Nutrition Examination Survey (NHANES) 2009-2010, with a sample size of 3371 participants (age 20-80 years). Toxoplasma infection was determined by the level of T. gondii IgG antibody in serum samples. Liver disease was assessed by liver injury biomarkers and the Fatty Liver Index (US-FLI). The evaluation of the association between T. gondii infection and liver disease included the calculation of the Mantel-Haenszel risk ratio (RRMH), Rho-Scott chi-square bivariate analyses, design-based t-tests, and linear and logistic regression models which were adjusted for demographic and anthropometric covariates.

RESULTS

Mean levels of aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were significantly more elevated in the T. gondii IgG-positive (IgG+) participants as compared to T. gondii-negative (IgG-) participants, p = 0.0435 and 0.0310, respectively. In linear regression analysis, exposure to T. gondii IgG+ had statistically significant positive associations with AST (p = 0.0211), alanine aminotransferase (ALT) (p = 0.0221), and gamma-glutamyl transferase (GGT) (p = 0.0258) after adjusting for BMI, age, gender, and race. T. gondii exposure was associated with an elevated relative risk of chronic liver disease (CLD) (RRMH = 1.26, 95% CI: 1.05-1.51). This association was more pronounced in certain occupations, such as construction, agriculture, forestry, and fishing, where Toxoplasma infection is more common (p = 0.0477). Moreover, Toxoplasma infection increased the odds of nonalcoholic fatty liver disease (NAFLD) (OR = 6.99, 95% CI = 1.85-26.32, p = 0.0237).

CONCLUSION

T. gondii IgG+ antibody was significantly associated with liver injury biomarkers (ALT, AST, GGT, and ALP) and an increased risk of CLD and NAFLD. Moreover, the association of Toxoplasma with CLD was more evident in specific occupations where the prevalence of Toxoplasma was high. The findings of this study provide insight into utilizing liver biomarkers and US-FLI to assess the health complications of Toxoplasma when imaging tests are not accessible.

"Food is Environmentally and Culturally Specific!": A Preliminary Qualitative Study on U.S. Immigrant Parents' Perceptions of School Lunch

Children spend most of their day hours in school, so the dietary choices they make during school days are important for their childhood development and later life. This research examined food choices among immigrant families with school-age children in Indiana, USA. Open-ended questions were answered by 52 immigrant parents in 2017. Parents who answered the questions had children in classes ranging from kindergarten to grade 12. NVivo 11 was used for the initial analysis of the dataset, and several themes were identified. After the initial analysis, the data were categorized into major themes to condense the themes. Thirty-eight (73%) of the respondents indicated that their children ate school lunch, 14 (27%) indicated that they prepared lunch for their children to eat at school, and 39 (75%), mostly from non-industrialized countries, indicated that their children ate their home-country staple foods for dinner and on non-school days. Parents indicated that schools are serving the needs of immigrant children by serving varieties of foods during lunchtime.

The Association of Per- and Polyfluoroalkyl Substances Serum Levels and Allostatic Load by Country of Birth and the Length of Time in the United States

Objectives: The aim of this study was to examine the association of per- and polyfluoroalkyl (PFAS) concentrations and allostatic load (AL) by the county of birth and the length of time in the United States of America (U.S.), in a representative sample of U.S. adults. Methods: Data from the 2007−2014 National Health and Nutrition Examination Survey (NHANES) were used in this cross-sectional study on the U.S. adults aged 20 and older. The analysis was stratified by the length of time in the U.S. and by the county of birth. In all, the sample contained those who were US-born (n = 10,264), Mexico-born (n = 4018), other Spanish speaking country-born (n = 2989), and other not−Hispanic speaking country-born (n = 3911). Poisson models were used to assess the differences in AL and PFAS levels depending on country of birth and length of time in the U.S. Results: Estimates indicated that those born in Other non−Spanish speaking counties had the highest PFAS levels among the country of birth category in the database. Regarding length of time in the U.S., those born in Mexico had low PFAS levels when their length of time in the U.S. was short. The Mexico-born category presented the most at-risk high serum PFAS levels, with AL levels increasing by length of time in the U.S. (p-value < 0.001). Conclusion: This study found that PFAS concentrations increased by the length of time residing in the U.S. Those born in other non−Hispanic counties had the highest PFAS levels among all the categories. In general, AL and PFAS levels are mostly associated with the length of time in the U.S., with foreign-born individuals having increased levels of both the longer they stay.

Methodologies for the collection of parameters to estimate dust/soil ingestion for young children

Background

Heavy metals, pesticides and a host of contaminants found in dust and soil pose a health risk to young children through ingestion. Dust/soil ingestion rates for young children can be estimated using micro-level activity time series (MLATS) as model inputs. MLATS allow for the generation of frequency and duration of children's contact activities, along with sequential contact patterns. Models using MLATS consider contact types, and transfer dynamics to assign mechanisms of contact and appropriate exposure factors for cumulative estimates of ingestion rates.

Objective

The objective of this study is to describe field implementation, data needs, advanced field collection, laboratory methodologies, and challenges for integrating into and updating a previously validated physical-stochastic MLATS-based model framework called the Child-Specific Aggregate Cumulative Human Exposure and Dose (CACHED) model. The manuscript focuses on describing the methods implemented in the current study.

Methods

This current multidisciplinary study (Dust Ingestion childRen sTudy [DIRT]) was implemented across three US regions: Tucson, Arizona; Miami, Florida and Greensboro, North Carolina. Four hundred and fifty participants were recruited between August 2021 to June 2023 to complete a 4-part household survey, of which 100 also participated in a field study.

Discussion

The field study focused on videotaping children's natural play using advanced unattended 360° cameras mounted for participants' tracking and ultimately conversion to MLATS. Additionally, children's hand rinses were collected before and after recording, along with indoor dust and outdoor soil, followed by advanced mass analysis. The gathered data will be used to quantify dust/soil ingestion by region, sociodemographic variables, age groups (from 6 months to 6 years), and other variables for indoor/outdoor settings within an adapted version of the CACHED model framework.

Significance

New innovative approaches for the estimation of dust/soil ingestion rates can potentially improve modeling and quantification of children's risks to contaminants from dust exposure.