-
[show abstract]
[hide abstract]
ABSTRACT: BACKGROUND: Nail salons represent a rapidly growing industry with mainly Vietnamese immigrant workers. Workers routinely handle nail products containing hazardous compounds, yet have limited accessible information to minimize workplace exposures. METHODS: We conducted a culturally appropriate pilot intervention on workplace chemical exposure reduction strategies. We trained eight Vietnamese owners, who then trained Vietnamese workers in their salons. We conducted pre-, mid-, and post-intervention assessments with workers, including an in-person survey and personal air monitoring of volatile compounds. RESULTS: Survey results suggested statistically significant increases for chemical knowledge and behavioral changes in glove and mask use, and a reduced prevalence of nose, throat, and skin irritations. Air monitoring results showed a net reduction for methyl methacrylate and total volatile organic compounds, but not for toluene. CONCLUSIONS: Worker education disseminated through salon owners to their workers can improve work-related knowledge, behavior, health symptoms, and exposures for select air contaminants, although more research is warranted. Am. J. Ind. Med. © 2012 Wiley Periodicals, Inc.
American Journal of Industrial Medicine 12/2012; · 1.63 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Although selection bias in case-control studies has been studied extensively, little is known about selection of cases and controls among various ethnic groups. This study compares racial differences in childhood cancer rates as estimated by case-control studies with various design features. It also compares estimates of racial distribution among cases as reported by case-control studies to those observed for an ideal case series with complete ascertainment of cases for these studies or in population-based cancer registries in corresponding geographic regions and calendar periods.
Peer-reviewed publications on childhood leukemia and brain tumors from North America, published between 1980 and 2007, were reviewed. Incidence data by race/ethnicity were compiled from research publications, federal cancer statistics, and cancer registries. Meta-analysis was conducted to assess racial/ethnic differences by study characteristics. Racial distributions of cases from published case-control studies were compared to those of a presumably noncensored case distribution (i.e. include both participating and non-participating cases in a case-control study) or cases recorded by cancer registries.
In interview-based case-control studies of childhood cancer, the proportion of Whites compared to non-Whites tended to be higher among controls than among cases; however, the opposite was true for record-based case-control studies. Additionally, the proportion of Whites tended to be higher among the participating cases in the published case-control studies compared to the proportion of Whites among the non-participating cases or in cancer registries.
Investigators need to consider differential participation by racial group as a potential source of bias in the interpretation of case-control study results.
Cancer epidemiology. 02/2012; 36(1):36-44.
-
[show abstract]
[hide abstract]
ABSTRACT: To examine whether the incidence of childhood cancer is elevated in children with birth defects but no chromosomal anomalies.
We examined cancer risk in a population-based cohort of children with and without major birth defects born between 1988 and 2004, by linking data from the California Birth Defects Monitoring Program, the California Cancer Registry, and birth certificates. Cox proportional hazards models generated hazard ratios (HRs) and 95% CIs based on person-years at risk. We compared the risk of childhood cancer in infants born with and without specific types of birth defects, excluding infants with chromosomal anomalies.
Of the 4869 children in the birth cohort with cancer, 222 had a major birth defect. Although the expected elevation in cancer risk was observed in children with chromosomal birth defects (HR, 12.44; 95% CI, 10.10-15.32), especially for the leukemias (HR, 28.99; 95% CI, 23.07-36.42), children with nonchromosomal birth defects also had an increased risk of cancer (HR, 1.58; 95% CI, 1.33-1.87), but instead for brain tumors, lymphomas, neuroblastoma, and germ cell tumors.
Children with nonchromosomal birth defects are at increased risk for solid tumors, but not leukemias. Dysregulation of early human development likely plays an important role in the etiology of childhood cancer.
The Journal of pediatrics 01/2012; 160(6):978-83. · 4.02 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The causes of childhood central nervous system (CNS) tumors are largely unknown. Birth characteristics have been examined as possible risk factors for childhood CNS tumors, although the studies have been underpowered and inconclusive. We hypothesized that birth anomalies and a mother's history of previous pregnancy losses, as a proxy for genetic defects, increase the risk for CNS tumors.
From the California Cancer Registry, we identified 3733 patients aged 0 to 14 years with CNS tumors, diagnosed from 1988 through 2006 and linked to a California birth certificate. Four controls were matched to each patient. We calculated odds ratios (ORs) for the reported presence of a birth defect and for history of pregnancy losses by using logistic regression, adjusted for race, Hispanic ethnicity, maternal age, birth weight, and birth order.
Offspring from mothers who had ≥ 2 fetal losses after 20 weeks' gestation had a threefold risk for CNS tumors (OR: 3.13 [95% confidence interval (CI): 1.32-7.41]) and a 14-fold risk for high-grade glioma (OR: 14.28 [95% CI: 1.56-130.65]). Birth defects increased risk for the CNS cancers medulloblastoma (OR: 1.70 [95% CI: 1.12-2.57]), primitive neuroectodermal tumor (OR: 3.64 [95% CI: 1.54-8.56]), and germ cell tumors (OR: 6.40 [95% CI: 2.09-19.56]).
Multiple pregnancy losses after 20 weeks' gestation and birth defects increase the risk of a childhood CNS tumor. Previous pregnancy losses and birth defects may be surrogate markers for gene defects in developmental pathways that lead to CNS tumorigenesis.
PEDIATRICS 08/2011; 128(3):e652-7. · 4.47 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Evaluate the risk of breast cancer associated with birth size among young California-born women.
Invasive breast cancer cases diagnosed 1988-2004 among women born in California during the 1960s were identified from the California Cancer Registry. Breast cancer cases (n = 3,712) were linked to their California birth records. Controls (n = 8,615) were randomly selected from California birth records for women, frequency matched to cases by birth year. Odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated from unconditional logistic regression.
The adjusted OR for breast cancer associated with the highest category of birth weight (≥4,000 g) was 1.12 (95% CI 0.89-1.41), p-trend = 0.02. The adjusted OR for the highest category of birth length (>20 inches) was 1.13 (95% CI 1.02-1.25), p-trend = 0.02. These relationships appeared to be confined to cases with estrogen receptor positive (ER+) tumors (p-trend ≤0.01) or progesterone receptor positive (PR+) tumors (p-trend ≤0.02). No significant associations were found among cases with ER or PR negative tumors.
Our results confirm previous findings of elevated breast cancer risk associated with increases in birth size. These risks may be confined to ER+ and PR+ tumors, highlighting the potential mechanistic role of sex steroid hormonal pathways.
Cancer Causes and Control 07/2011; 22(10):1461-70. · 2.88 Impact Factor
-
Julie Von Behren,
Logan G Spector,
Beth A Mueller,
Susan E Carozza,
Eric J Chow,
Erin E Fox,
Scott Horel,
Kimberly J Johnson,
Colleen McLaughlin,
Susan E Puumala,
Julie A Ross,
Peggy Reynolds
[show abstract]
[hide abstract]
ABSTRACT: The causes of childhood cancers are largely unknown. Birth order has been used as a proxy for prenatal and postnatal exposures, such as frequency of infections and in utero hormone exposures. We investigated the association between birth order and childhood cancers in a pooled case-control dataset. The subjects were drawn from population-based registries of cancers and births in California, Minnesota, New York, Texas and Washington. We included 17,672 cases <15 years of age who were diagnosed from 1980 to 2004 and 57,966 randomly selected controls born 1970-2004, excluding children with Down syndrome. We calculated odds ratios and 95% confidence intervals using logistic regression, adjusted for sex, birth year, maternal race, maternal age, multiple birth, gestational age and birth weight. Overall, we found an inverse relationship between childhood cancer risk and birth order. For children in the fourth or higher birth order category compared to first-born children, the adjusted OR was 0.87 (95% CI: 0.81, 0.93) for all cancers combined. When we examined risks by cancer type, a decreasing risk with increasing birth order was seen in the central nervous system tumors, neuroblastoma, bilateral retinoblastoma, Wilms tumor and rhabdomyosarcoma. We observed increased risks with increasing birth order for acute myeloid leukemia but a slight decrease in risk for acute lymphoid leukemia. These risk estimates were based on a very large sample size, which allowed us to examine rare cancer types with greater statistical power than in most previous studies, however the biologic mechanisms remain to be elucidated.
International Journal of Cancer 06/2011; 128(11):2709-16. · 5.44 Impact Factor
-
Thu Quach,
Robert Gunier,
Alisha Tran, Julie Von Behren,
Phuong-An Doan-Billings,
Kim-Dung Nguyen,
Linda Okahara,
Benjamin Yee-Bun Lui,
Mychi Nguyen,
Jessica Huynh,
Peggy Reynolds
[show abstract]
[hide abstract]
ABSTRACT: We engaged Vietnamese nail salon workers in a community-based participatory research (CBPR) study to measure personal and area concentrations of solvents in their workplace.
We measured average work-shift concentrations of toluene, ethyl acetate, and isopropyl acetate among 80 workers from 20 salons using personal air monitors. We also collected area samples from 3 salons using summa canisters.
For personal measurements, the arithmetic mean was 0.53 parts per million (range = 0.02-5.50) for ethyl acetate, 0.04 parts per million (range = 0.02-0.15) for isopropyl acetate, and 0.15 parts per million (range = 0.02-1.0) for toluene. Area measurements were lower in comparison, but we detected notable levels of methyl methacrylate, a compound long banned from nail products. Predictors of solvent levels included different forms of ventilation and whether the salon was located in an enclosed building.
Using a CBPR approach that engaged community members in the research process contributed to the successful recruitment of salon workers. Measured levels of toluene, methyl methacrylate, and total volatile organic compounds were higher than recommended guidelines to prevent health symptoms such as headaches, irritations, and breathing problems, which were frequently reported in this workforce.
American Journal of Public Health 05/2011; 101 Suppl 1:S271-6. · 3.93 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To compare breast cancer risk among young Asian and Pacific Islander (API) women to White women, all of whom were born in California during the 1960s.
We used previously-collected data from a population-based case-control study in which breast cancer cases were linked to their California birth records.
California, US.
Invasive breast cancer cases diagnosed 1988-2004 among women aged < 45 were identified from the population-based California Cancer Registry. Breast cancer cases (n = 3,799) were linked to their California birth records. Controls (n = 17,461) were randomly selected from California birth records for females, frequency matched to cases by birth year.
Odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated using logistic regression.
Among young women born in California, API women had higher risks of breast cancer than Whites (OR = 1.62, 95% CI: 1.35-1.94). Among APIs, the risks were highest for women of Filipina (OR = 1.72, 95% Cl: 1.15-2.56) and Japanese ancestry (OR = 1.59, 95% Cl 1.20-2.10).
Our finding of breast cancer risk among young API women who were born in California that exceeds that of young White women highlights the need for further evaluations of breast cancer risk among young API women and underscores the need to consider both ancestry and migration status in such evaluations.
Ethnicity & disease 01/2011; 21(2):196-201. · 0.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Health concerns have been pronounced for cosmetologists and manicurists, who are exposed daily to cosmetic products containing known or suspected human carcinogens and endocrine disruptors. In this retrospective cohort study, the authors used probabilistic record linkage between California's statewide cosmetology licensee and cancer surveillance files to identify newly diagnosed invasive cancers among female workforce members during 1988-2005. Rate ratios and 95% confidence intervals for cancer among workforce members compared with the general female population in California were estimated via Poisson regression. For comparison, site-specific proportional incidence ratios were computed. The authors identified 9,044 cancer cases in a cohort of 325,228 licensees. Rate ratios for all sites combined suggested lower incidence among both cosmetologists (rate ratio = 0.84, 95% confidence interval (CI): 0.82, 0.86) and manicurists (rate ratio = 0.87, 95% CI: 0.84, 0.90). Proportional incidence ratios were modestly elevated for thyroid cancer among all licensees (proportional incidence ratio = 1.13, 95% CI: 1.04, 1.23) and for lung cancer among manicurists (proportional incidence ratio = 1.21, 95% CI: 1.07, 1.36). Although there did not appear to be a cancer excess, these findings may be artifactually influenced by limitations in demographic information available from the licensee files. Additionally, the relatively young ages of cohort members and demographic shifts in the industry composition in recent years suggest a need for further follow-up.
American journal of epidemiology 09/2010; 172(6):691-9. · 5.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine whether birth characteristics related to maternal-fetal health in utero are associated with the development of childhood central nervous system tumors.
We identified, from the California Cancer Registry, 3733 children under age 15 diagnosed with childhood central nervous system tumors between 1988 and 2006 and linked these cases to their California birth certificates. Four controls per case, matched on birth date and sex, were randomly selected from the same birth files. We evaluated associations of multiple childhood CNS tumor subtypes with birth weight and birth order.
Low birth weight was associated with a reduced risk of low-grade gliomas (OR=0.67; 95% CI, 0.46 to 0.97) and high birth weight was associated with increased risk of high-grade gliomas (OR=1.57; 95% CI, 1.16 to 2.12). High birth order (fourth or higher) was associated with decreased risk of low-grade gliomas (OR=0.75; 95% CI, 0.56 to 0.99) and increased risk of high-grade gliomas (OR=1.32; 95% CI, 1.01 to 1.72 for second order).
Factors that drive growth in utero may increase the risk of low-grade gliomas. There may be a similar relationship in high-grade gliomas, although other factors, such as early infection, may modify this association. Additional investigation is warranted to validate and further define these findings.
The Journal of pediatrics 09/2010; 157(3):450-5. · 4.02 Impact Factor
-
Eric J Chow,
Susan E Puumala,
Beth A Mueller,
Susan E Carozza,
Erin E Fox,
Scott Horel,
Kimberly J Johnson,
Colleen C McLaughlin,
Peggy Reynolds, Julie Von Behren,
Logan G Spector
[show abstract]
[hide abstract]
ABSTRACT: Children of different racial/ethnic backgrounds have varying risks of cancer. However, to the authors' knowledge, few studies to date have examined cancer occurrence in children of mixed ancestry.
This population-based case-control study examined cancer among children aged <15 years using linked cancer and birth registry data from 5 US states from 1978 through 2004. Data were available for 13,249 cancer cases and 36,996 controls selected from birth records. Parental race/ethnicity was determined from birth records. Logistic regression analysis was used to examine the association of cancer with different racial/ethnic groups.
Compared with whites, blacks had a 28% decreased risk of cancer (odds ratio [OR], 0.72; 95% confidence interval [95% CI], 0.65-0.80), whereas both Asians and Hispanics had an approximate 15% decrease. Children of mixed white/black ancestry also were found to be at decreased risk (OR, 0.71; 95% CI, 0.56-0.90), but estimates for mixed white/Asian and white/Hispanic children did not differ from those of whites. Compared with whites: 1) black and mixed white/black children had decreased ORs for acute lymphoblastic leukemia (OR, 0.39 [95% CI, 0.31-0.49] and OR, 0.58 [95% CI, 0.37-0.91], respectively); 2) Asian and mixed white/Asian children had decreased ORs for brain tumors (OR, 0.51 [95% CI, 0.39-0.68] and OR, 0.79 [95% CI, 0.54-1.16], respectively); and 3) Hispanic and mixed white/Hispanic children had decreased ORs for neuroblastoma (OR, 0.51 [95% CI, 0.42-0.61] and OR, 0.67 [95% CI, 0.50-0.90], respectively).
Children of mixed ancestry tend to have disease risks that are more similar to those of racial/ethnic minority children than the white majority group. This tendency may help formulate etiologic studies designed to study possible genetic and environmental differences more directly.
Cancer 06/2010; 116(12):3045-53. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Ambient exposure from residential proximity to applications of agricultural pesticides may contribute to the risk of childhood acute lymphoblastic leukemia (ALL). Using residential histories collected from the families of 213 ALL cases and 268 matched controls enrolled in the Northern California Childhood Leukemia Study, the authors assessed residential proximity within a half-mile (804.5m) of pesticide applications by linking address histories with reports of agricultural pesticide use. Proximity was ascertained during different time windows of exposure, including the first year of life and the child's lifetime through the date of diagnosis for cases or reference for controls. Agricultural pesticides were categorized a priori into groups based on similarities in toxicological effects, physicochemical properties, and target pests or uses. The effects of moderate and high exposure for each group of pesticides were estimated using conditional logistic regression. Elevated ALL risk was associated with lifetime moderate exposure, but not high exposure, to certain physicochemical categories of pesticides, including organophosphates, chlorinated phenols, and triazines, and with pesticides classified as insecticides or fumigants. A similar pattern was also observed for several toxicological groups of pesticides. These findings suggest future directions for the identification of specific pesticides that may play a role in the etiology of childhood leukemia.
Environmental Research 09/2009; 109(7):891-9. · 3.40 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Obesity is a risk factor for asthma, particularly in women, but few cohort studies have evaluated abdominal obesity which reflects metabolic differences in visceral fat known to influence systemic inflammation. A study was undertaken to examine the relationship between the prevalence of asthma and measures of abdominal obesity and adult weight gain in addition to body mass index (BMI) in a large cohort of female teachers.
Prevalence odds ratios (ORs) for current asthma were calculated using multivariable linear modelling, adjusting for age, smoking and race/ethnicity.
Of the 88 304 women in the analyses, 13% (n = 11,500) were obese (BMI > or = 30 kg/m(2)) at baseline; 1334 were extremely obese (BMI > or = 40 kg/m(2)). Compared with those of normal weight, the adjusted OR for adult-onset asthma increased from 1.40 (95% confidence interval (CI) 1.31 to 1.49) for overweight women to 3.30 (95% CI 2.85 to 3.82) for extremely obese women. Large waist circumference (>88 cm) was associated with increased asthma prevalence, even among women with a normal BMI (OR 1.37, 95% CI 1.18 to 1.59). Among obese women the OR for asthma was greater in those who were also abdominally obese than in women whose waist was < or = 88 cm (2.36 vs 1.57). Obese and overweight women were at greater risk of severe asthma episodes, measured by urgent medical visits and hospital admissions.
This study confirms the association between excess weight and asthma severity and prevalence, and showed that a large waist was associated with increased asthma prevalence even among women considered to have normal body weight.
Thorax 09/2009; 64(10):889-93. · 6.84 Impact Factor
-
Logan G Spector,
Susan E Puumala,
Susan E Carozza,
Eric J Chow,
Erin E Fox,
Scott Horel,
Kimberly J Johnson,
Colleen C McLaughlin,
Peggy Reynolds, Julie Von Behren,
Beth A Mueller
[show abstract]
[hide abstract]
ABSTRACT: The risk of hepatoblastoma is strongly increased among children with very low birth weight (<1500 g). Because data on very low birth weight and other childhood cancers are sparse, we examined the risk of malignancy with very low birth weight in a large data set.
We combined case-control data sets created by linking the cancer and birth registries of California, Minnesota, New York, Texas, and Washington states, which included 17672 children diagnosed as having cancer at 0 to 14 years of age and 57966 randomly selected control subjects. Unconditional logistic regression analysis was used to examine the association of cancer with very low birth weight and moderately low birth weight (1500-1999 g and 2000-2499 g, respectively), compared with moderate/high birth weight (>or=2500 g), with adjustment for gender, gestational age, birth order, plurality, maternal age, maternal race, state, and year of birth.
Most childhood cancers were not associated with low birth weights. However, retinoblastomas and gliomas other than astrocytomas and ependymomas were possibly associated with very low birth weight. The risk of other gliomas was also increased among children weighing 1500 to 1999 g at birth.
These data suggested no association between most cancers and very low birth weight, with the exception of the known association of hepatoblastoma and possibly moderately increased risks of other gliomas and retinoblastoma, which may warrant confirmation.
PEDIATRICS 08/2009; 124(1):96-104. · 4.47 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In epidemiologic studies, neighborhood characteristics are often assigned to individuals based on a single residence despite the fact that people frequently move and, for most cancer outcomes, the relevant time-window of exposure is not known. The authors evaluated residential mobility patterns for a population-based series of childhood leukemia cases enrolled in the Northern California Childhood Leukemia Study.
Complete residential history from 1 year before birth to date of diagnosis was obtained for 380 cases diagnosed between 1995 and 2002. All residences were assigned U.S. Census block group designations using a geographic information system.
Overall, two-thirds (65.8%) of children had moved between birth and diagnosis, and one-third (34.5%) moved during the first year of life. Approximately 25% of the mothers had moved during the year before the child's birth. Multivariable analysis indicated greater residential mobility to be associated with older age of the child at diagnosis, younger age of the mother at child's birth, and lower household income. Among those who had moved, residential urban/rural status for birth and diagnosis residences changed for about 20% of subjects, and neighborhood socioeconomic status for 35%.
These results suggest that neighborhood attribute estimates in health studies should account for patterns of residential mobility. Estimates based on a single residential location at a single point in time may lead to different inferences.
Annals of epidemiology 05/2009; 19(11):834-40. · 2.95 Impact Factor
-
Kimberly J Johnson,
Susan E Carozza,
Eric J Chow,
Erin E Fox,
Scott Horel,
Colleen C McLaughlin,
Beth A Mueller,
Susan E Puumala,
Peggy Reynolds, Julie Von Behren,
Logan G Spector
[show abstract]
[hide abstract]
ABSTRACT: Few risk factors for childhood cancer are well-established. We investigated whether advancing parental age increases childhood cancer risk.
We assessed the relationship between parental age and childhood cancer in a case-control study using pooled population-based data. Our pooling was based on linked cancer and birth registry records from New York, Washington, Minnesota, Texas, and California. Subjects included 17,672 cancer cases diagnosed at ages 0-14 years during 1980-2004 and 57,966 controls born during 1970-2004. Individuals with Down syndrome were excluded. Odds ratios and 95% confidence intervals were calculated by logistic regression for the association between parental age and childhood cancer after adjustment for sex, birth weight, gestational age, birth order, plurality, maternal race, birth year, and state.
Positive linear trends per 5-year maternal age increase were observed for childhood cancers overall (odds ratio = 1.08 [95% confidence interval = 1.06-1.10]) and 7 of the 10 most frequent diagnostic groups: leukemia (1.08 [1.05-1.11]), lymphoma (1.06 [1.01-1.12]), central nervous system tumors (1.07 [1.03-1.10]), neuroblastoma (1.09 [1.04-1.15]), Wilms' tumor (1.16 [1.09-1.22]), bone tumors (1.10 [1.00-1.20]), and soft tissue sarcomas (1.10 [1.04-1.17]). No maternal age effect was noted for retinoblastoma, germ cell tumors, or hepatoblastoma. Paternal age was not independently associated with most childhood cancers after adjustment for maternal age.
Our results suggest that older maternal age increases risk for most common childhood cancers. Investigation into possible mechanisms for this association is warranted.
Epidemiology (Cambridge, Mass.) 05/2009; 20(4):475-83. · 5.51 Impact Factor
-
Susan E Puumala,
Susan E Carozza,
Eric J Chow,
Erin E Fox,
Scott Horel,
Kimberly J Johnson,
Colleen McLaughlin,
Beth A Mueller,
Peggy Reynolds, Julie Von Behren,
Logan G Spector
[show abstract]
[hide abstract]
ABSTRACT: Although several studies have found no change or a decreased risk of childhood cancer in twins, few have controlled for potential confounders such as birth weight. We examined the association of birth plurality and childhood cancer in pooled data from five U.S. states (California, Minnesota, New York, Texas, and Washington) using linked birth-cancer registry data. The data, excluding children with Down syndrome or who died before 28 days of life, included 17,672 cases diagnosed from 1980 to 2004 at ages 28 days to 14 years and 57,966 controls with all cases and controls born from 1970 to 2004. Analyses were restricted to children weighing <or=4,000 g at birth. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using unconditional logistic regression adjusting for sex, gestational age, birth weight, birth order, maternal age, maternal race, state of birth, and birth year. Children who were multiples had no difference in risk of cancer overall (OR, 0.93; 95% CI, 0.82-1.07), but a borderline reduced risk of Wilms' tumor (OR, 0.65; 95% CI, 0.39-1.09). For children diagnosed <2 y of age there was a reduced risk of Wilms' tumor (OR, 0.27; 95% CI, 0.09-0.86) and neuroblastoma (OR, 0.46; 95% CI, 0.25-0.84) and an increased risk of fibrosarcoma (OR, 5.81; 95% CI, 1.53-22.11). Higher-order multiple birth (triplets or higher) was not associated with childhood cancer. Our analysis suggests that mechanisms other than birth weight and gestational age may influence the lower risk of Wilms' tumor and neuroblastoma in multiple births.
Cancer Epidemiology Biomarkers & Prevention 01/2009; 18(1):162-8. · 4.12 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Exposures to carcinogenic compounds from vehicle exhaust may increase childhood leukemia risk, and the timing of this exposure may be important.
We examined the association between traffic density and childhood leukemia risk for three time periods: birth, time of diagnosis, and lifetime average, based on complete residential history in a case-control study. Cases were rapidly ascertained from participating hospitals in northern and central California between 1995 and 2002. Controls were selected from birth records, individually matched on age, sex, race, and Hispanic ethnicity. Traffic density was calculated by estimating total vehicle miles traveled per square mile within a 500-foot (152 meter) radius area around each address. We used conditional logistic regression analyses to account for matching factors and to adjust for household income.
We included 310 cases of acute lymphocytic leukemias (ALL) and 396 controls in our analysis. The odds ratio for ALL and residential traffic density above the 75th percentile, compared with subjects with zero traffic density, was 1.17 [95% confidence interval (95% CI), 0.76-1.81] for residence at diagnosis and 1.11 (95% CI, 0.70-1.78) for the residence at birth. For average lifetime traffic density, the odds ratio was 1.24 (95% CI, 0.74-2.08) for the highest exposure category.
Living in areas of high traffic density during any of the exposure time periods was not associated with increased risk of childhood ALL in this study.
Cancer Epidemiology Biomarkers & Prevention 10/2008; 17(9):2298-301. · 4.12 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The peak incidence of neuroblastoma during infancy suggests that certain prenatal or perinatal factors may be etiologically important. In this population-based study, California birth certificates were identified for 508 (86%) neuroblastoma cases diagnosed at less than 5 years of age between 1988 and 1997. For each case, two controls, matched on date of birth and gender, were randomly selected from the statewide birth registry. Results of multivariate analyses showed a reduced risk for children of Hispanic (odds ratio (OR) = 0.57, 95% confidence interval (CI): 0.43, 0.76) and "other" (OR = 0.56, 95% CI: 0.37, 0.85) race/ethnicity, compared with non-Hispanic Whites. Postterm/high birth weight delivery was associated with an increased risk of neuroblastoma compared with term/normal birth weight delivery among infants (OR = 6.99, 95% CI: 1.07, 45.55), while preterm birth appeared suggestive of a reduced risk among children 1-4 years of age. For children in this age group, the risk of neuroblastoma was elevated for cesarean delivery compared with vaginal delivery (OR = 1.72, 95% CI: 1.21, 2.47), and, for infants, the risk was reduced if the mother had had multiple previous pregnancies (OR = 0.39, 95% CI: 0.22, 0.69). These data suggest that etiologic factors associated with the prenatal and perinatal periods may be specific to age at neuroblastoma diagnosis.
American Journal of Epidemiology 04/2007; 165(5):486-95. · 5.22 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The male sex ratio at birth (or the proportion of male births in a population) has been suggested as a sentinel environmental health indicator. Usually around 51%, the proportion may be dramatically decreased in offspring of persons with chemical exposures. Recent publications from the USA and elsewhere have noted a small but apparently declining male birth proportion, suggesting the effect of some environmental exposures. This paper sought to examine these trends more closely in California's large and diverse population.
Using computerised birth certificate data, time trends were examined by multivariate linear and spline regression, controlling for demographic factors.
California.
About 15 million births from 1960 to 1996.
In the raw data, the male birth proportion is indeed declining. However, during this period, there were also shifts in demographics that influence the sex ratio. Controlling for birth order, parents' age, and race/ethnicity, different trends emerged. White births (which account for over 80%) continued to show a statistically significant decline, while other racial groups showed non-statistically significant declines (Japanese, Native American, other), little or no change (black), or an increase (Chinese). Finally, when the white births were divided into Hispanic and non-Hispanic (possible since 1982), it was found that both white subgroups suggest an increase in male births.
This analysis shows that the decline in male births in California is largely attributable to changes in demographics.
Journal of Epidemiology & Community Health 01/2006; 59(12):1047-53. · 3.19 Impact Factor
