The Diesel Exhaust in Miners Study: A Nested Case–Control Study of Lung Cancer and Diesel Exhaust

BACKGROUND Most studies of the association between diesel exhaust exposure and lung cancer suggest a modest, but consistent, increased risk. However, to our knowledge, no study to date has had quantitative data on historical diesel exposure coupled with adequate sample size to evaluate the exposure-response relationship between diesel exhaust and lung cancer. Our purpose was to evaluate the relationship between quantitative estimates of exposure to diesel exhaust and lung cancer mortality after adjustment for smoking and other potential confounders. METHODS We conducted a nested case-control study in a cohort of 12 315 workers in eight non-metal mining facilities, which included 198 lung cancer deaths and 562 incidence density-sampled control subjects. For each case subject, we selected up to four control subjects, individually matched on mining facility, sex, race/ethnicity, and birth year (within 5 years), from all workers who were alive before the day the case subject died. We estimated diesel exhaust exposure, represented by respirable elemental carbon (REC), by job and year, for each subject, based on an extensive retrospective exposure assessment at each mining facility. We conducted both categorical and continuous regression analyses adjusted for cigarette smoking and other potential confounding variables (eg, history of employment in high-risk occupations for lung cancer and a history of respiratory disease) to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Analyses were both unlagged and lagged to exclude recent exposure such as that occurring in the 15 years directly before the date of death (case subjects)/reference date (control subjects). All statistical tests were two-sided. RESULTS We observed statistically significant increasing trends in lung cancer risk with increasing cumulative REC and average REC intensity. Cumulative REC, lagged 15 years, yielded a statistically significant positive gradient in lung cancer risk overall (P (trend) = .001); among heavily exposed workers (ie, above the median of the top quartile [REC ≥ 1005 μg/m(3)-y]), risk was approximately three times greater (OR = 3.20, 95% CI = 1.33 to 7.69) than that among workers in the lowest quartile of exposure. Among never smokers, odd ratios were 1.0, 1.47 (95% CI = 0.29 to 7.50), and 7.30 (95% CI = 1.46 to 36.57) for workers with 15-year lagged cumulative REC tertiles of less than 8, 8 to less than 304, and 304 μg/m(3)-y or more, respectively. We also observed an interaction between smoking and 15-year lagged cumulative REC (P (interaction) = .086) such that the effect of each of these exposures was attenuated in the presence of high levels of the other. CONCLUSION Our findings provide further evidence that diesel exhaust exposure may cause lung cancer in humans and may represent a potential public health burden

How to determine life expectancy change of air pollution mortality: a time series study

<p>Abstract</p> <p>Background</p> <p>Information on life expectancy (LE) change is of great concern for policy makers, as evidenced by discussions of the "harvesting" (or "mortality displacement") issue, i.e. how large an LE loss corresponds to the mortality results of time series (TS) studies. Whereas loss of LE attributable to chronic air pollution exposure can be determined from cohort studies, using life table methods, conventional TS studies have identified only deaths due to acute exposure, during the immediate past (typically the preceding one to five days), and they provide no information about the LE loss per death.</p> <p>Methods</p> <p>We show how to obtain information on population-average LE loss by extending the observation window (largest "lag") of TS to include a sufficient number of "impact coefficients" for past exposures ("lags"). We test several methods for determining these coefficients. Once all of the coefficients have been determined, the LE change is calculated as time integral of the relative risk change after a permanent step change in exposure.</p> <p>Results</p> <p>The method is illustrated with results for daily data of non-accidental mortality from Hong Kong for 1985 - 2005, regressed against PM₁₀and SO₂with observation windows up to 5 years. The majority of the coefficients is statistically significant. The magnitude of the SO₂coefficients is comparable to those for PM₁₀. But a window of 5 years is not sufficient and the results for LE change are only a lower bound; it is consistent with what is implied by other studies of long term impacts.</p> <p>Conclusions</p> <p>A TS analysis can determine the LE loss, but if the observation window is shorter than the relevant exposures one obtains only a lower bound.</p

Dental Microwear and Diet of the Plio-Pleistocene Hominin Paranthropus boisei

The Plio-Pleistocene hominin Paranthropus boisei had enormous, flat, thickly enameled cheek teeth, a robust cranium and mandible, and inferred massive, powerful chewing muscles. This specialized morphology, which earned P. boisei the nickname “Nutcracker Man”, suggests that this hominin could have consumed very mechanically challenging foods. It has been recently argued, however, that specialized hominin morphology may indicate adaptations for the consumption of occasional fallback foods rather than preferred resources. Dental microwear offers a potential means by which to test this hypothesis in that it reflects actual use rather than genetic adaptation. High microwear surface texture complexity and anisotropy in extant primates can be associated with the consumption of exceptionally hard and tough foods respectively. Here we present the first quantitative analysis of dental microwear for P. boisei. Seven specimens examined preserved unobscured antemortem molar microwear. These all show relatively low complexity and anisotropy values. This suggests that none of the individuals consumed especially hard or tough foods in the days before they died. The apparent discrepancy between microwear and functional anatomy is consistent with the idea that P. boisei presents a hominin example of Liem's Paradox, wherein a highly derived morphology need not reflect a specialized diet

Inter-population variations in concentrations, determinants of and correlations between 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE): a cross-sectional study of 3161 men and women from Inuit and European populations

BACKGROUND: The study is part of a collaborative project (Inuendo), aiming to assess the impact of dietary persistent organochlorine pollutants (POPs) on human fertility. The aims with the present study are to analyze inter-population variations in serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE), to assess inter-population variations in biomarker correlations, and to evaluate the relative impact of different determinants for the inter-individual variations in POP-biomarkers. METHOD: In study populations of 3161 adults, comprising Greenlandic Inuits, Swedish fishermen and their wives, and inhabitants from Warsaw, Poland and Kharkiv, Ukraine, serum concentrations of CB-153 and p,p'-DDE, were analysed by gas chromatography-mass spectrometry. RESULTS: The median serum concentrations of CB-153 were for male and female Inuits 200 and 110, for Swedish fishermen 190 and their wives 84, for Kharkiv men and women 44 and 27, and for Warsaw men and women 17 and 11 ng/g lipids, respectively. The median serum concentrations of p,p'-DDE were for Kharkiv men and women 930 and 650, for male and female Inuits 560 and 300, for Warsaw men and women 530 and 380, and for Swedish fishermen 240 and their wives 140 ng/g lipids, respectively. The correlation coefficients between CB-153 and p,p'-DDE varied between 0.19 and 0.92, with the highest correlation among Inuits and the lowest among men from Warsaw. Men had averagely higher serum concentrations of CB-153 and p,p'-DDE, and there were positive associations between age and the POP-biomarkers, whereas the associations with BMI and smoking were inconsistent. Dietary seafood was of importance only in the Inuit and Swedish populations. CONCLUSION: CB-153 concentrations were much higher in Inuits and Swedish fishermen's populations than in the populations from Eastern Europe, whereas the pattern was different for p,p'-DDE showing highest concentrations in the Kharkiv population. The correlations between the POP-biomarkers varied considerably between the populations, underlining that exposure sources differ and that the choice of representative biomarkers of overall POP exposure has to be based on an analysis of the specific exposure situation for each population. Age and gender were consistent determinants of serum POPs; seafood was of importance only in the Inuit and Swedish populations

Circulating 25-Hydroxyvitamin D and the Risk of Rarer Cancers: Design and Methods of the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

The Cohort Consortium Vitamin D Pooling Project of Rarer Cancers (VDPP), a consortium of 10 prospective cohort studies from the United States, Finland, and China, was formed to examine the associations between circulating 25-hydroxyvitamin D (25(OH)D) concentrations and the risk of rarer cancers. Cases (total n = 5,491) included incident primary endometrial (n = 830), kidney (n = 775), ovarian (n = 516), pancreatic (n = 952), and upper gastrointestinal tract (n = 1,065) cancers and non-Hodgkin lymphoma (n = 1,353) diagnosed in the participating cohorts. At least 1 control was matched to each case on age, date of blood collection (1974–2006), sex, and race/ethnicity (n = 6,714). Covariate data were obtained from each cohort in a standardized manner. The majority of the serum or plasma samples were assayed in a central laboratory using a direct, competitive chemiluminescence immunoassay on the DiaSorin LIAISON platform (DiaSorin, Inc., Stillwater, Minnesota). Masked quality control samples included serum standards from the US National Institute of Standards and Technology. Conditional logistic regression analyses were conducted using clinically defined cutpoints, with 50–<75 nmol/L as the reference category. Meta-analyses were also conducted using inverse-variance weights in random-effects models. This consortium approach permits estimation of the association between 25(OH)D and several rarer cancers with high accuracy and precision across a wide range of 25(OH)D concentrations

Short-term exposure to traffic-related air pollution and daily mortality in London, UK.

Epidemiological studies have linked daily concentrations of urban air pollution to mortality, but few have investigated specific traffic sources that can inform abatement policies. We assembled a database of >100 daily, measured and modelled pollutant concentrations characterizing air pollution in London between 2011 and 2012. Based on the analyses of temporal patterns and correlations between the metrics, knowledge of local emission sources and reference to the existing literature, we selected, a priori, markers of traffic pollution: oxides of nitrogen (general traffic); elemental and black carbon (EC/BC) (diesel exhaust); carbon monoxide (petrol exhaust); copper (tyre), zinc (brake) and aluminium (mineral dust). Poisson regression accounting for seasonality and meteorology was used to estimate the percentage change in risk of death associated with an interquartile increment of each pollutant. Associations were generally small with confidence intervals that spanned 0% and tended to be negative for cardiovascular mortality and positive for respiratory mortality. The strongest positive associations were for EC and BC adjusted for particle mass and respiratory mortality, 2.66% (95% confidence interval: 0.11, 5.28) and 2.72% (0.09, 5.42) per 0.8 and 1.0 μg/m(3), respectively. These associations were robust to adjustment for other traffic metrics and regional pollutants, suggesting a degree of specificity with respiratory mortality and diesel exhaust containing EC/BC

Influence of Primary Care Physician Availability and Socioeconomic Deprivation on Breast Cancer from 1988 to 2008: A Spatio-Temporal Analysis

Breast cancer is the most commonly diagnosed cancer and the second leading cause of cancer death among women in the United States. It is unclear how county-level primary care physician (PCP) availability and socioeconomic deprivation affect the spatial and temporal variation of breast cancer incidence and mortality.We used the 1988-2008 public-use county-based data from nine Surveillance, Epidemiology, and End Results (SEER) programs to analyze the temporal and spatial disparity of PCP availability and socioeconomic deprivation on early-stage incidence, advanced-stage incidence and breast cancer mortality. The spatio-temporal analysis was implemented by a novel structural additive modeling approach.Greater PCP availability was significantly associated with higher early-stage incidence, advanced-stage incidence and mortality during the entire study period while socioeconomic deprivation was significantly negatively associated with early-stage incidence, advanced-stage incidence, and mortality up to 1992. However, the observed influence of PCP availability and socioeconomic deprivation varied by county.We showed important associations of PCP availability and socioeconomic deprivation with the three breast cancer indicators. However, the effect of these associations varied over time and across counties. The association of PCP availability and socioeconomic deprivation was stronger in selected counties

Acute and Chronic Effects of Particles on Hospital Admissions in New-England

Background: Many studies have reported significant associations between exposure to $PM_{2.5}$ and hospital admissions, but all have focused on the effects of short-term exposure. In addition all these studies have relied on a limited number of $PM_{2.5}$ monitors in their study regions, which introduces exposure error, and excludes rural and suburban populations from locations in which monitors are not available, reducing generalizability and potentially creating selection bias. Methods Using our novel prediction models for exposure combining land use regression with physical measurements (satellite aerosol optical depth) we investigated both the long and short term effects of $PM_{2.5}$ exposures on hospital admissions across New-England for all residents aged 65 and older. We performed separate Poisson regression analysis for each admission type: all respiratory, cardiovascular disease (CVD), stroke and diabetes. Daily admission counts in each zip code were regressed against long and short-term $PM_{2.5}$ exposure, temperature, socio-economic data and a spline of time to control for seasonal trends in baseline risk. Results: We observed associations between both short-term and long-term exposure to $PM_{2.5}$ and hospitalization for all of the outcomes examined. In example, for respiratory diseases, for every10-µg/m$^3$ increase in short-term $PM_{2.5}$ exposure there is a 0.70 percent increase in admissions (CI = 0.35 to 0.52) while concurrently for every10-µg/m$^3$ increase in long-term $PM_{2.5}$ exposure there is a 4.22 percent increase in admissions (CI = 1.06 to 4.75). Conclusions: As with mortality studies, chronic exposure to particles is associated with substantially larger increases in hospital admissions than acute exposure and both can be detected simultaneously using our exposure models