Loraine A. Escobedo

Sources and contents of air pollution affecting term low birth weight in Los Angeles County, California, 2001-2008

BACKGROUND Low birth weight (LBW, <2500 g) has been associated with exposure to air pollution, but it is still unclear which sources or components of air pollution might be in play. The association between ultrafine particles and LBW has never been studied. OBJECTIVES To study the relationships between LBW in term born infants and exposure to particles by size fraction, source and chemical composition, and complementary components of air pollution in Los Angeles County (California, USA) over the period 2001-2008. METHODS Birth certificates (n=960,945) were geocoded to maternal residence. Primary particulate matter (PM) concentrations by source and composition were modeled. Measured fine PM, nitrogen dioxide and ozone concentrations were interpolated using empirical Bayesian kriging. Traffic indices were estimated. Associations between LBW and air pollution metrics were examined using generalized additive models, adjusting for maternal age, parity, race/ethnicity, education, neighborhood income, gestational age and infant sex. RESULTS Increased LBW risks were associated with the mass of primary fine and ultrafine PM, with several major sources (especially gasoline, wood burning and commercial meat cooking) of primary PM, and chemical species in primary PM (elemental and organic carbon, potassium, iron, chromium, nickel, and titanium but not lead or arsenic). Increased LBW risks were also associated with total fine PM mass, nitrogen dioxide and local traffic indices (especially within 50 m from home), but not with ozone. Stronger associations were observed in infants born to women with low socioeconomic status, chronic hypertension, diabetes and a high body mass index. CONCLUSIONS This study supports previously reported associations between traffic-related pollutants and LBW and suggests other pollution sources and components, including ultrafine particles, as possible risk factors.

A Statewide Nested Case-Control Study of Preterm Birth and Air Pollution by Source and Composition: California, 2001-2008.

Background: Preterm birth (PTB) has been associated with exposure to air pollution, but it is unclear whether effects might vary among air pollution sources and components. Objectives: We studied the relationships between PTB and exposure to different components of air pollution, including gases and particulate matter (PM) by size fraction, chemical composition, and sources. Methods: Fine and ultrafine PM (respectively, PM2.5 and PM0.1) by source and composition were modeled across California over 2000–2008. Measured PM2.5, nitrogen dioxide, and ozone concentrations were spatially interpolated using empirical Bayesian kriging. Primary traffic emissions at fine scale were modeled using CALINE4 and traffic indices. Data on maternal characteristics, pregnancies, and birth outcomes were obtained from birth certificates. Associations between PTB (n = 442,314) and air pollution exposures defined according to the maternal residence at birth were examined using a nested matched case–control approach. Analyses were adjusted for maternal age, race/ethnicity, education and neighborhood income. Results: Adjusted odds ratios for PTB in association with interquartile range (IQR) increases in average exposure during pregnancy were 1.133 (95% CI: 1.118, 1.148) for total PM2.5, 1.096 (95% CI: 1.085, 1.108) for ozone, and 1.079 (95% CI: 1.065, 1.093) for nitrogen dioxide. For primary PM, the strongest associations per IQR by source were estimated for onroad gasoline (9–11% increase), followed by onroad diesel (6–8%) and commercial meat cooking (4–7%). For PM2.5 composition, the strongest positive associations per IQR were estimated for nitrate, ammonium, and secondary organic aerosols (11–14%), followed by elemental and organic carbon (2–4%). Associations with local traffic emissions were positive only when analyses were restricted to births with residences geocoded at the tax parcel level. Conclusions: In our statewide nested case–control study population, exposures to both primary and secondary pollutants were associated with an increase in PTB. Citation: Laurent O, Hu J, Li L, Kleeman MJ, Bartell SM, Cockburn M, Escobedo L, Wu J. 2016. A statewide nested case–control study of preterm birth and air pollution by source and composition: California, 2001–2008. Environ Health Perspect 124:1479–1486; http://dx.doi.org/10.1289/ehp.1510133

Low birth weight and air pollution in California: Which sources and components drive the risk?

INTRODUCTION Intrauterine growth restriction has been associated with exposure to air pollution, but there is a need to clarify which sources and components are most likely responsible. This study investigated the associations between low birth weight (LBW, <2500g) in term born infants (≥37 gestational weeks) and air pollution by source and composition in California, over the period 2001-2008. METHODS Complementary exposure models were used: an empirical Bayesian kriging model for the interpolation of ambient pollutant measurements, a source-oriented chemical transport model (using California emission inventories) that estimated fine and ultrafine particulate matter (PM2.5 and PM0.1, respectively) mass concentrations (4km×4km) by source and composition, a line-source roadway dispersion model at fine resolution, and traffic index estimates. Birth weight was obtained from California birth certificate records. A case-cohort design was used. Five controls per term LBW case were randomly selected (without covariate matching or stratification) from among term births. The resulting datasets were analyzed by logistic regression with a random effect by hospital, using generalized additive mixed models adjusted for race/ethnicity, education, maternal age and household income. RESULTS In total 72,632 singleton term LBW cases were included. Term LBW was positively and significantly associated with interpolated measurements of ozone but not total fine PM or nitrogen dioxide. No significant association was observed between term LBW and primary PM from all sources grouped together. A positive significant association was observed for secondary organic aerosols. Exposure to elemental carbon (EC), nitrates and ammonium were also positively and significantly associated with term LBW, but only for exposure during the third trimester of pregnancy. Significant positive associations were observed between term LBW risk and primary PM emitted by on-road gasoline and diesel or by commercial meat cooking sources. Primary PM from wood burning was inversely associated with term LBW. Significant positive associations were also observed between term LBW and ultrafine particle numbers modeled with the line-source roadway dispersion model, traffic density and proximity to roadways. DISCUSSION This large study based on complementary exposure metrics suggests that not only primary pollution sources (traffic and commercial meat cooking) but also EC and secondary pollutants are risk factors for term LBW.

In Utero and Early-Life Exposure to Ambient Air Toxics and Childhood Brain Tumors: A Population-Based Case–Control Study in California, USA

Background: Little is known about the influence of environmental factors on the etiology of childhood brain tumors. Objectives: We examined risks for brain tumors in children after prenatal and infant exposure to monitored ambient air toxics. Methods: We ascertained all cases of medulloblastoma, central nervous system primitive neuroectodermal tumor (PNET), and astrocytoma before 6 years of age diagnosed in 1990–2007 from the California Cancer Registry and selected controls randomly from birth rolls matched by birth year. Exposures to air toxics during pregnancy/infancy for 43 PNET, 34 medulloblastoma, and 106 astrocytoma cases and 30,569 controls living within 5 mi of a monitor were determined. With factor analysis we assessed the correlational structures of 26 probable carcinogenic toxics, and estimated odds ratios by brain tumor type in logistic regression models. Results: PNETs (≤ 38 cases) were positively associated with interquartile range (IQR) increases in prenatal exposure to acetaldehyde [odds ratio (OR) = 2.30; 95% CI: 1.44, 3.67], 1,3-butadiene (OR = 2.23; 95% CI: 1.28, 3.88), benzene, and toluene; and with IQR increases in exposure during the first year of life to ortho-dichlorobenzene (OR = 3.27; 95% CI: 1.17, 9.14), 1,3-butadiene (OR = 3.15; 95% CI: 1.57, 6.32), and benzene. All exposures except ortho-dichlorobenzene loaded on the same factor. Medulloblastoma (≤ 30 cases) was associated with prenatal exposure to polycyclic aromatic hydrocarbons (PAHs combined: OR = 1.44; 95% CI: 1.15, 1.80). Exposures to lead and some PAHs during the first year of life were positively associated with astrocytoma, but the confidence intervals included the null value (e.g., for lead, OR = 1.40; 95% CI: 0.97, 2.03). Conclusions: Our data suggest that in utero and infancy exposures to air toxics generated by industrial and road traffic sources may increase the risk of PNET and medulloblastoma, with limited support for increased risks for astrocytoma in children up to age 6. Citation: von Ehrenstein OS, Heck JE, Park AS, Cockburn M, Escobedo L, Ritz B. 2016. In Utero and early-life exposure to ambient air toxics and childhood brain tumors: a population-based case–control study in California, USA. Environ Health Perspect 124:1093–1099; http://dx.doi.org/10.1289/ehp.1408582

Are HPV vaccination services accessible to high-risk communities? A spatial analysis of HPV-associated cancer and Chlamydia rates and safety-net clinics.

PurposeWhile HPV vaccines can greatly benefit adolescents and young women from high-risk areas, little is known about whether safety-net immunization services are geographically accessible to communities at greatest risk for HPV-associated diseases. We explore the spatial relationship between areas with high HPV risk and proximity to safety-net clinics from an ecologic perspective.MethodsWe used cancer registry data and Chlamydia surveillance data to identify neighborhoods within Los Angeles County with high risk for HPV-associated cancers. We examined proximity to safety-net clinics among neighborhoods with the highest risk. Proximity was measured as the shortest distance between each neighborhood center and the nearest clinic and having a clinic within 3 miles of each neighborhood center.ResultsThe average 5-year non-age-adjusted rates were 1,940 cases per 100,000 for Chlamydia and 60 per 100,000 for HPV-associated cancers. A large majority, 349 of 386 neighborhoods with high HPV-associated cancer rates and 532 of 537 neighborhoods with high Chlamydia rates, had a clinic within 3 miles of the neighborhood center. Clinics were more likely to be located within close proximity to high-risk neighborhoods in the inner city. High-risk neighborhoods outside of this urban core area were less likely to be near accessible clinics.ConclusionsThe majority of high-risk neighborhoods were geographically near safety-net clinics with HPV vaccination services. Due to low rates of vaccination, these findings suggest that while services are geographically accessible, additional efforts are needed to improve uptake. Programs aimed to increase awareness about the vaccine and to link underserved groups to vaccination services are warranted.

Teledermatology as a tool to improve access to care for medically underserved populations: A retrospective descriptive study

Photo included at any point No 1976 (21%) Yes 7523 (79%) Photo included initially Yes 7337 (98%) No 186 (2%) Photo adequate Yes 7160 (95%) No 363 (5%) Length of dialogue exchange #1000 characters 5902 (62%) [1000 characters 3596 (38%) PCP suspects malignancy Yes 2072 (22%) No 7427 (78%) Dermatologist suspects malignancy Yes 860 (9%) No 8639 (91%) PCP suspects melanoma Yes 663 (7%) No 8836 (93%) Dermatologist suspects melanoma Yes 182 (2%) No 9317 (98%)

The role of spatially-derived access-to-care characteristics in melanoma prevention and control in Los Angeles county

Abstract Among 10,068 incident cases of invasive melanoma, we examined the effects of patient characteristics and access‐to‐care on the risk of advanced melanoma. Access‐to‐care was defined in terms of census tract‐level sociodemographics, health insurance, cost of dermatological services and appointment wait‐times, clinic density and travel distance. Public health insurance and education level were the strongest predictors of advanced melanomas but were modified by race/ethnicity and poverty: Hispanic whites and high‐poverty neighborhoods were worse off than non‐Hispanic whites and low‐poverty neighborhoods. Targeting high‐risk, underserved Hispanics and high‐poverty neighborhoods (easily identified from existing data) for early melanoma detection may be a cost‐efficient strategy to reduce melanoma mortality.

Conflicts and Contradictions in Current Skin Cancer Screening Guidelines

Purpose of ReviewThe purpose of this paper is to review skin cancer screening guidelines from major public health/medical organizations.Recent FindingsNo consensus exists on whether or not screening to prevent skin cancer is warranted.SummaryThe best evidence of screening efficacy should come from population-based randomized trials, but is unlikely to exist due to feasibility constraints. Consequently, consensus should be built from observational/non-randomized designs, such as the SCREEN study in Germany. Current guidelines often focus on melanoma alone, while potential benefits of screening for non-melanoma skin cancers (NMSC) are largely overlooked. There may be less room for doubt regarding the value of screening, if both diseases were considered. Further, targeted approaches, i.e., screening only in high-risk populations, remain poorly defined and untested. Continuing to state that there is insufficient evidence to recommend screening leads to confusion about whether or not to screen and is unlikely to result in substantial changes to the morbidity of NMSC and significant mortality from melanoma.

Phytochemicals and Naturally Occurring Substances in the Chemoprevention of Skin Cancer

Purpose of ReviewNon-melanoma skin cancer outnumbers all other cancers combined by three to four-fold while melanoma is the fifth most common cancer overall, and the deadliest form of skin cancer. Despite treatment advancements in the past several decades, incidence continues to rise. Phytochemicals and other naturally occurring substances may provide sustainable chemopreventive solutions. The purpose of this study is to review the key findings from the literature and report on the level of evidence based on study design.Recent FindingsA comprehensive PubMed search was completed from 1984 to present using keywords “skin cancer chemoprevention” alone and with “phytochemicals,” “alternative,” “essential oils,” and “vitamins.” This search demonstrated that the literature strongly endorses the role of naturally occurring substances in the context of skin cancer chemoprevention, however the literature is predominantly comprised of data based on in vitro and animal based models.SummaryPrior to acceptance into mainstream practice, high quality prospective studies to evaluate the role of naturally occurring compounds in the context of skin cancer chemoprevention are indicated.