A Cancer Risk Assessment of Inner-City Teenagers Living in New York City and Los Angeles

BACKGROUND: The Toxics Exposure Assessment Columbia–Harvard (TEACH) project assessed exposures and cancer risks from urban air pollutants in a population of high school teenagers in New York City (NYC) and Los Angeles (LA). Forty-six high school students participated in NYC and 41 in LA, most in two seasons in 1999 and 2000, respectively. METHODS: Personal, indoor home, and outdoor home 48-hr samples of volatile organic compounds (VOCs), aldehydes, particulate matter with aerodynamic diameter ≤ 2.5 μm, and particle-bound elements were collected. Individual cancer risks for 13 VOCs and 6 particle-bound elements were calculated from personal concentrations and published cancer unit risks. RESULTS: The median cumulative risk from personal VOC exposures for this sample of NYC high school students was 666 per million and was greater than the risks from ambient exposures by a factor of about 5. In the LA sample, median cancer risks from VOC personal exposures were 486 per million, about a factor of 4 greater than ambient exposure risks. The VOCs with the highest cancer risk included 1,4-dichlorobenzene, formaldehyde, chloroform, acetaldehyde, and benzene. Of these, benzene had the greatest contributions from outdoor sources. All others had high contributions from indoor sources. The cumulative risks from personal exposures to the elements were an order of magnitude lower than cancer risks from VOC exposures. CONCLUSIONS: Most VOCs had median upper-bound lifetime cancer risks that exceeded the U.S. Environmental Protection Agency (EPA) benchmark of 1 × 10(−6) and were generally greater than U.S. EPA modeled estimates, more so for compounds with predominant indoor sources. Chromium, nickel, and arsenic had median personal cancer risks above the U.S. EPA benchmark with exposures largely from outdoors and other microenvironments. The U.S. EPA–modeled concentrations tended to overestimate personal cancer risks for beryllium and chromium but underestimate risks for nickel and arsenic

Ambient Metals, Elemental Carbon, and Wheeze and Cough in New York City Children through 24 Months of Age

Rationale: The effects of exposure to specific components of ambient fine particulate matter (PM2.5), including metals and elemental carbon (EC), have not been fully characterized in young children. Objectives: To compare temporal associations among PM2.5; individual metal constituents of ambient PM2.5, including nickel (Ni), vanadium (V), and zinc (Zn); and EC and longitudinal reports of respiratory symptoms through 24 months of age. Methods: Study participants were selected from the Columbia Center for Children's Environmental Health birth cohort recruited in New York City between 1998 and 2006. Respiratory symptom data were collected by questionnaire every 3 months through 24 months of age. Ambient pollutant data were obtained from state-operated stationary monitoring sites located within the study area. For each subject, 3-month average inverse-distance weighted concentrations of Ni, V, Zn, EC, and PM2.5 were calculated for each symptom-reporting period based on the questionnaire date and the preceding 3 months. Associations between pollutants and symptoms were characterized using generalized additive mixed effects models, adjusting for sex, ethnicity, environmental tobacco smoke exposure, and calendar time. Measurements and Main Results: Increases in ambient Ni and V concentrations were associated significantly with increased probability of wheeze. Increases in EC were associated significantly with cough during the cold/flu season. Total PM2.5 was not associated with wheeze or cough. Conclusions: These results suggest that exposure to ambient metals and EC from heating oil and/or traffic at levels characteristic of urban environments may be associated with respiratory symptoms among very young children

Assessment of Benzo(a)pyrene-equivalent Carcinogenicity and Mutagenicity of Residential Indoor versus Outdoor Polycyclic Aromatic Hydrocarbons Exposing Young Children in New York City

The application of benzo(a)pyrene (BaP)-toxic equivalent factor to polycyclic aromatic hydrocarbons (PAH) concentrations can provide a more accurate risk assessment from environmental exposure to PAH. We hypothesized that BaP-equivalent toxicity determined following residential air monitoring among young urban children may vary by season. Residential indoor and outdoor air levels of PAH measured over two-weeks in a cohort of 5–6 year old children (n = 260) in New York City were normalized to the cancer and mutagen potency equivalent factor of BaP (BaP = 1). Data are presented as carcinogenic equivalents (BaP-TEQ) and mutagenic equivalents (BaP-MEQ) for the sum of 8 PAH (∑8PAH; MW ³ 228) and individual PAH and compared across heating versus nonheating seasons. Results show that heating compared to nonheating season was associated significantly with higher (BaP-TEQ)∑8PAH and (BaP-MEQ)∑8PAH both indoors and outdoors (p less than 0.001). Outdoor (BaP-TEQ)∑8PAH and (BaP-MEQ)∑8PAH were significantly higher than the corresponding indoor measures during the heating season (p less than 0.01). These findings suggest that at levels encountered in New York City air, especially during the heating season, residential exposure to PAH may pose an increased risk of cancer and mutation

Urban Adolescents Readily Comply with a Complicated Asthma Research Protocol

Purpose: Adolescents are often cited as having poor rates of compliance with medical regimens and research protocols. We quantified compliance in a cohort of urban adolescents participating in a complex research protocol in which measures were obtained without direct supervision by research personnel. Methods: A total of 54 early adolescents ages 10–13 were asked to wear a vest containing a personal air pollutant exposure monitor for two 24-hour periods and to perform daily peak expiratory flow (PEF) for six consecutive days. Compliance with wearing the vest was measured by comparing accelerometer data from a device within the vest to one worn continuously on the child's wrist. Daily PEF data were recorded using an electronic meter. Results: A priori definition of compliance was met by 85% of the adolescents by wearing the exposure monitoring vest and 72% by performing PEF. Conclusions: These findings suggest that early adolescents can be compliant with complex research protocols that are needed to help bridge gaps in pediatric asthma research

Association of recent exposure to ambient metals on fractional exhaled nitric oxide in 9–11 year old inner-city children

Exposure to ambient metals in urban environments has been associated with wheeze, and emergency room visits and hospitalizations due to respiratory illness. However, the effect of ambient metals exposure on airway inflammation, and how these associations may be modified by seroatopy, has not been determined. Fractional exhaled nitric oxide (FENO) is a reliable proxy marker of airway inflammation. We hypothesized that recent ambient concentrations of Ni, V, Zn and Fe would be associated differentially with proximal and distal fractions of exhaled NO, and that these associations would be modified by seroatopy. As part of the Columbia Center for Children’s Environmental Health (CCCEH) birth cohort study, 9–11 year old children (n = 192) were evaluated. Ambient measures of Ni, V, Zn and Fe were obtained from a local central monitoring site and averaged over 9 days based on three 24 h measures every third day. Fractional exhaled nitric oxide (FENO) samples were obtained at constant flows of 50 (FENO50), 83 and 100 mL/s, and used to determine surrogate measures for proximal (JNO) and alveolar (Calv) inflammation. Seroatopy was determined by specific IgE at age 7. Data were analyzed using multivariable linear regression. Ambient V and Fe concentrations were associated positively with FENO50 (p = 0.018, p = 0.027). Ambient Fe was associated positively with JNO (p = 0.017). Ambient Ni and V concentrations were associated positively with Calv (p = 0.004, p = 0.018, respectively). A stronger association of Ni concentrations with Calv was observed among the children with seroatopy. These results suggest that ambient metals are associated differentially with different fractions of FENO production, and this relationship may be modified by seroatopy

Association of recent exposure to ambient metals on fractional exhaled nitric oxide in 9–11 year old inner-city children

Exposure to ambient metals in urban environments has been associated with wheeze, and emergency room visits and hospitalizations due to respiratory illness. However, the effect of ambient metals exposure on airway inflammation, and how these associations may be modified by seroatopy, has not been determined. Fractional exhaled nitric oxide (FENO) is a reliable proxy marker of airway inflammation. We hypothesized that recent ambient concentrations of Ni, V, Zn and Fe would be associated differentially with proximal and distal fractions of exhaled NO, and that these associations would be modified by seroatopy. As part of the Columbia Center for Children’s Environmental Health (CCCEH) birth cohort study, 9–11 year old children (n = 192) were evaluated. Ambient measures of Ni, V, Zn and Fe were obtained from a local central monitoring site and averaged over 9 days based on three 24 h measures every third day. Fractional exhaled nitric oxide (FENO) samples were obtained at constant flows of 50 (FENO50), 83 and 100 mL/s, and used to determine surrogate measures for proximal (JNO) and alveolar (Calv) inflammation. Seroatopy was determined by specific IgE at age 7. Data were analyzed using multivariable linear regression. Ambient V and Fe concentrations were associated positively with FENO50 (p = 0.018, p = 0.027). Ambient Fe was associated positively with JNO (p = 0.017). Ambient Ni and V concentrations were associated positively with Calv (p = 0.004, p = 0.018, respectively). A stronger association of Ni concentrations with Calv was observed among the children with seroatopy. These results suggest that ambient metals are associated differentially with different fractions of FENO production, and this relationship may be modified by seroatopy

Polycyclic aromatic hydrocarbon exposure, obesity and childhood asthma in an urban cohort

Background: Exposure to traffic-related air pollutants, including polycyclic aromatic hydrocarbons (PAHs) from traffic emissions and other combustion sources, and childhood obesity, have been implicated as risk factors for developing asthma. However, the interaction between these two on asthma among young urban children has not been studied previously. Methods: Exposure to early childhood PAHs was measured by two week residential indoor monitoring at age 5–6 years in the Columbia Center for Children's Environmental Health birth cohort (n=311). Semivolatile [e.g., methylphenanthrenes] and nonvolatile [e.g., benzo(a)pyrene] PAHs were monitored. Obesity at age 5 was defined as a body mass index (BMI) greater than or equal to the 95th percentile of the year 2000 age- and sex-specific growth charts (Center for Disease Control). Current asthma and recent wheeze at ages 5 and 7 were determined by validated questionnaires. Data were analyzed using a modified Poisson regression in generalized estimating equations (GEE) to estimate relative risks (RR), after adjusting for potential covariates. Results: Neither PAH concentrations or obesity had a main effect on asthma or recent wheeze. In models stratified by presence/absence of obesity, a significant positive association was observed between an interquartile range (IQR) increase in natural log-transformed 1-methylphenanthrene (RR [95% CI]: 2.62 [1.17–5.88] with IQRln=0.76), and 9-methylphenanthrene (2.92 [1.09–7.82] with IQRln=0.73) concentrations and asthma in obese children (n=63). No association in non-obese (n=248) children was observed at age 5 (Pinteraction<0.03). Similar associations were observed for 3-methylphenanthrene, 9-methylphenanthrene, and 3,6-dimethylphenanthrene at age 7. Conclusions: Obese young children may be more likely to develop asthma in association with greater exposure to PAHs, and methylphenanthrenes in particular, than non-obese children

Effects of Floor Level and Building Type on Residential Levels of Outdoor and Indoor Polycyclic Aromatic Hydrocarbons, Black Carbon, and Particulate Matter in New York City

Consideration of the relationship between residential floor level and concentration of traffic-related airborne pollutants may predict individual residential exposure among inner city dwellers more accurately. Our objective was to characterize the vertical gradient of residential levels of polycyclic aromatic hydrocarbons (PAH; dichotomized into Σ8PAHsemivolatile (MW 178–206), and Σ8PAHnonvolatile (MW 228–278), black carbon (BC), PM2.5 (particulate matter) by floor level (FL), season and building type. We hypothesize that PAH, BC and PM2.5 concentrations may decrease with higher FL and the vertical gradients of these compounds would be affected by heating season and building type. PAH, BC and PM2.5 were measured over a two-week period outdoor and indoor of the residences of a cohort of 5–6 year old children (n = 339) living in New York City’s Northern Manhattan and the Bronx. Airborne-pollutant levels were analyzed by three categorized FL groups (0–2nd, 3rd–5th, and 6th–32nd FL) and two building types (low-rise versus high-rise apartment building). Indoor Σ8PAHnonvolatile and BC levels declined with increasing FL. During the nonheating season, the median outdoor Σ8PAHnonvolatile, but not Σ8PAHsemivolatile, level at 6th–2nd FL was 1.5–2 times lower than levels measured at lower FL. Similarly, outdoor and indoor BC concentrations at 6th–32nd FL were significantly lower than those at lower FL only during the nonheating season (p less than 0.05). In addition, living in a low-rise building was associated significantly with higher levels of Σ8PAHnonvolatile and BC. These results suggest that young inner city children may be exposed to varying levels of air pollutants depending on their FL, season, and building type