sj-docx-1-ehi-10.1177_11786302231184751 – Supplemental material for Consumer Awareness and Health Risk Perceptions of Pesticide Residues in Fruits and Vegetables in Kampala Metropolitan Area in Uganda

Supplemental material, sj-docx-1-ehi-10.1177_11786302231184751 for Consumer Awareness and Health Risk Perceptions of Pesticide Residues in Fruits and Vegetables in Kampala Metropolitan Area in Uganda by Charles Ssemugabo, Asa Bradman, John C Ssempebwa and David Guwatudde in Environmental Health Insights</p

Determining Fetal Manganese Exposure from Mantle Dentine of Deciduous Teeth

Studies addressing health effects of manganese (Mn) excess or deficiency during prenatal development are hampered by a lack of biomarkers that can reconstruct fetal exposure. We propose a method using the neonatal line, a histological feature in deciduous teeth, to identify regions of mantle dentine formed at different prenatal periods. Micromeasurements of Mn in these regions may be used to reconstruct exposure at specific times in fetal development. To test our hypothesis, we recruited pregnant women before 20 weeks gestation from a cohort of farmworkers exposed to Mn-containing pesticides. We collected house floor dust samples and mother’s blood during the second trimester; umbilical cord blood at birth; and shed deciduous incisors when the child was ∼7 years of age. Mn levels in mantle dentine formed during the second trimester (as ⁵⁵Mn:⁴³Ca area under curve) were significantly associated with floor dust Mn loading (<i>r</i>_spearman = 0.40; <i>p</i> = 0.0005; <i>n</i> = 72). Furthermore, ⁵⁵Mn:⁴³Ca in sampling points immediately adjacent the neonatal line were significantly associated to Mn concentrations in cord blood (<i>r</i>_spearman = 0.70; <i>p</i> = 0.003; <i>n</i> = 16). Our results support that Mn levels in mantle dentine are useful in discerning perinatal Mn exposure, offering a potentially important biomarker for the study of health effects due to environmental Mn exposure

Volatile organic compound emissions from markers used in preschools, schools, and homes

<p>There is little published research examining volatile organic compound (VOC) emissions from art markers. In this study, we characterised VOC emission rates from markers commonly used by children at home and in school, and by teachers in their classrooms. We developed a method to measure standardised emission rates under controlled laboratory conditions, focusing on four major marker types: permanent, dry erase, highlighter, and washable. Emission rates for other less common marker types were also measured. We conducted additional experiments determining changes in emission profiles over short and long time periods (several hours up to daily use over about 2 months), as well as during periods of active drawing. We tested a total of 101 markers and report emission rates for 60 chemicals. Permanent and dry erase markers had average total VOC emissions more than 400 times higher than highlighters and washable markers. Alcohols were the most highly emitted class of VOCs from permanent and dry erase markers. Some chemicals associated with potentially serious health concerns were also identified. Future studies that employ full-scale chamber experiments and personal monitoring in classrooms to measure children’s actual exposures are recommended.</p

Phthalate Exposure and Risk Assessment in California Child Care Facilities

Approximately 13 million U.S. children less than 6 years old spend some time in early childhood education (ECE) facilities where they may be exposed to potentially harmful chemicals during critical periods of development. We measured five phthalate esters in indoor dust (<i>n</i> = 39) and indoor and outdoor air (<i>n</i> = 40 and 14, respectively) at ECE facilities in Northern California. Dust and airborne concentrations were used to perform a probabilistic health risk assessment to compare estimated exposures with risk levels established for chemicals causing reproductive toxicity and cancer under California’s Proposition 65. Di­(2-ethylhexyl) phthalate (DEHP) and butyl benzyl phthalate (BBzP) were the dominant phthalates present in floor dust (medians = 172.2 and 46.8 μg/g, respectively), and dibutyl phthalate (DBP), diethyl phthalate (DEP), and diisobutyl phthalate (DIBP) were the dominant phthalates in indoor air (medians = 0.52, 0.21, and 0.10 μg/m³, respectively). The risk assessment results indicate that 82–89% of children in California ECE had DBP exposure estimates exceeding reproductive health benchmarks. Further, 8–11% of children less than 2 years old had DEHP exposure estimates exceeding cancer benchmarks. This is the largest study to measure phthalate exposure in U.S. ECE facilities and findings indicate wide phthalate contamination and potential risk to developing children

Polybrominated Diphenyl Ethers, Polychlorinated Biphenyls, and 2,2-Bis(4-chlorophenyl)-1,1-dichloroethene in 7- and 9‑Year-Old Children and Their Mothers in the Center for the Health Assessment of Mothers and Children of Salinas Cohort

We report longitudinal serum concentrations of select persistent organic pollutants (POPs) in children at ages 7 and 9 years and in their mothers prenatally and again when the children were 9 years old. The participating families were enrolled in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), a longitudinal birth cohort study of low-income Hispanic families residing in the Salinas Valley, California. We observed decreasing concentrations in the mothers with year of serum collection (2009 vs 2011) for six out of seven polybrominated diphenyl ether (PBDE) congeners and for 2,2′,4,4′,5-pentachlorobiphenyl (CB-99; <i>p</i> < 0.05). The 9-year-old children had similarly decreasing serum concentrations of all seven PBDE congeners, CB-99, and 2,2′,3,4,4′,5′- and 2,3,3′,4,4′,6-hexachlorobiphenyl (CB-138/158) with year of serum collection (2009 vs 2011; <i>p</i> < 0.05). In mixed effect models accounting for weight gain as the children aged from 7 to 9 years, we observed an annual decrease (−8.3% to −13.4%) in tri- to hexaBDE concentrations (<i>p</i> < 0.001), except for 2,2′,3,4,4′-tetrabromodiphenyl ether (BDE-85) and 2,2′,4,4′,5,5′-hexabromodiphenyl ether (BDE-153). The concentrations of these congeners were not associated with time of serum collection and instead showed an −0.9% to −2.6% decrease per kilogram of weight gain during the study period (<i>p</i> < 0.05). In the case of tetra- to heptachlorobiphenyls, we observed −0.5% to −0.7% decrease in serum concentration per kilogram of weight gain (<i>p</i> < 0.05) and −3.0% to −3.7% decrease in serum concentration per year of aging (<i>p</i> < 0.05), except for 2,3′,4,4′,5-pentachlorobiphenyl (CB-118) and 2,2′,4,4′,5,5′-hexachlorobiphenyl (CB-153), which were not associated with time of serum draw. 2,2-Bis­(4-chlorophenyl)-1,1-dichloroethene (<i>p</i>,<i>p</i>′-DDE) decreased −2.4%/kg of weight gain between the two sampling points (<i>p</i> < 0.001). These findings suggest that as children grow, dilution in a larger body size plays an important role in explaining reductions in body burden in the case of traditional POPs such as PCBs and <i>p</i>,<i>p</i>′-DDE. By contrast, in the case of PBDEs, reductions are likely explained by reduction in exposure, as illustrated by decreased concentrations in more recent years, possibly amplified by presumed shorter biological half-life than other POPs

Factors Associated with Serum Polybrominated Diphenyl Ether (PBDE) Levels Among School-Age Children in the CHAMACOS Cohort

Polybrominated diphenyl ethers (PBDEs) are a class of flame retardants historically used in textiles, furniture, and electronic products. Recent studies have documented widespread PBDE exposure to humans, with higher levels measured in children than adults. We analyzed 10 tri- to hepta-BDE congener levels in blood collected from 7-year old Mexican-American children living in an agriculture community in California (<i>n</i> = 272). The most frequently detected PBDE congeners in child serum were BDE-47, -99, -100, and -153, all of which were measured in >99% of the children. We used multiple linear regression models to examine associations between child total PBDE levels (ng/g lipid) and determinants of exposure. Factors positively associated with higher PBDE levels in the children were total PBDE levels in maternal serum during pregnancy, duration of exclusive breastfeeding, and having no safe places to play in their neighborhood. Child BMI was inversely associated with serum PBDE levels (regression p-values <0.05). Our findings confirm that exposure to the penta-BDE mixture is ongoing, and that Mexican-American children living in California may be experiencing higher PBDE exposure from their environment compared to children sampled from the general U.S. population. Additional research is needed to assess the health impacts of these exposures