Engineered nanomaterials exposure in the production of graphene

<p>The objective of this study was to obtain the multi-metric occupational exposure assessment to graphene family nanomaterials (GFNs) particles of workers engaged in the large-scale production of graphene. The study design consisted of the combination of (i) direct-reading instruments, used to evaluate the total particle number concentrations relative to the background concentration (time series with spatial approach) and the mean size-dependent characteristics of particles (mean diameter and surface-area concentration) and (ii) filter-based air sampling for the determination of size-resolved particle mass concentrations. The data obtained from direct reading measurement were then used to estimate the 8-h time weighted average (8-h TWA) exposure to GFNs particles for workers involved in different working tasks. Workers were generally exposed to 8-h TWA GFNs particle levels lower than the proposed reference value (40,000 particle/cm³). Furthermore, despite high short-term exposure conditions were present during specific operations of the production process, the possibility of significant exposure peaks is not likely to be expected. The estimated 8-h TWA concentration showed differences between the unexposed (<100 particle/cm³; <0.05 µg/m³) and exposed subjects (mean concentration ranging from 909 to 6438 particle/cm³ and from 0.38 to 3.86 µg/m³). The research outcomes can be of particular interest because the exposure of workers in real working conditions was assessed with a multi-metric approach; in this regard, the study suggests that workers who are directly involved in some specific working task (material sampling for quality control) have higher potential for occupational exposure than operators who are in charge of routine production work.</p> <p>© 2016 American Association for Aerosol Research</p

Observed (Obs) and expected (Exp) cases of de-novo tumors, Standardized Incidence Ratios (SIR), and 95% Confidence Intervals (95% CI) among 494 adult recipients who underwent primary liver transplantation, 1983–2009, by gender. Reference: pool of Italian cancer registries.

<p>Observed (Obs) and expected (Exp) cases of de-novo tumors, Standardized Incidence Ratios (SIR), and 95% Confidence Intervals (95% CI) among 494 adult recipients who underwent primary liver transplantation, 1983–2009, by gender. Reference: pool of Italian cancer registries.</p

Representative scatter plots (Day 1 vs. Day 4 blood DNA methylation measures) of the biomarkers with highest (<i>IL-6</i>, panel A) and lowest (<i>APC</i>, panel B) intra-class correlation coefficients.

<p>Representative scatter plots (Day 1 vs. Day 4 blood DNA methylation measures) of the biomarkers with highest (<i>IL-6</i>, panel A) and lowest (<i>APC</i>, panel B) intra-class correlation coefficients.</p

Clinical characteristics of 494 adult recipients who underwent primary liver transplantation, 1983–2009.

<p>Clinical characteristics of 494 adult recipients who underwent primary liver transplantation, 1983–2009.</p

Correlations of intraclass correlation coefficients (ICCs) with DNA methylation levels and genomic characteristics of the sequences analyzed.

<p>The panels show correlations of ICCs for each of the methylation biomarkers with content of guanosine and cytosine (G+C, panel A); ratio of observed/expected CpG dinucleotides (CpG o/e; panel B); distance of repeat elements from 3′ (panel C); distance of repeat elements from 5′ (panel D); DNA methylation mean on Day 1 (panel E); range of DNA methylation on Day 1 (panel F). The scatter plots use ICC values subtracted of pyrosequencing measurement errors (ICC₁) and estimated from models adjusted by PM₁₀ exposure levels, age, current smoking, and percent blood granulocytes. Each data point corresponds to the ICC₁ value for one biomarker, as indicated by the corresponding label.</p

Blood DNA methylation levels (%mC) in Day 1 and Day 4 samples.

<p>Blood DNA methylation levels (%mC) in Day 1 and Day 4 samples.</p

Kaplan-Meier survivor functions (thick lines) and 95% confidence intervals (95% CI, thin lines) after liver transplantation or DNT onset.

<p>Kaplan-Meier survivor functions (thick lines) and 95% confidence intervals (95% CI, thin lines) after liver transplantation or DNT onset.</p

Sequence characteristics of the DNA methylation markers analyzed.

*<p><i>Alu</i> and LINE-1 were not considered, as repeat elements have multiple locations across the human genome with different context sequence characteristics.</p

Relative risks and 95% confidence intervals for lung cancer overall and by other medical conditions in the United States Veterans Affairs Inpatient Cohort: White males (n = 3,669,224) with at least one hospital admission between July 1, 1969 and September 30, 1996.

<p><b>Abbreviations:</b> RR, relative risk; CI, confidence interval; COPD, Chronic Obstructive Pulmonary Disease; ICD, International Classification of Disease.</p>a<p>ICD-8 & ICD-9, code 296 which includes depression and bipolar I disease.</p>b<p>Adjusted for number of visits, age, latency, calendar time, and by the stratifying variables (COPD, alcohol and substance dependence and abuse, and schizophrenia) when appropriate.</p>c<p>Percentage of participants with mood disorders within each medical condition.</p>d<p>ICD-8 & ICD-9, codes 490–492.</p>e<p>ICD-8 & ICD-9, codes 291, 303, 305.0, 535.3, 571.0–571.3, 980.0.</p>f<p>ICD-8 & ICD-9, codes 304–305.</p>g<p>ICD-8 & ICD-9, code 295.</p><p><b>Note:</b> Numbers of participants may not sum to total due to missing data.</p

Numbers and percentages of cases and controls with a first-degree relative (mother, father, siblings, or children) with history of mood disorders by demographic and behavioral characteristics in the EAGLE Study, Italy, 2002–2005.

<p><b>Abbreviation:</b> EAGLE, Environment And Genetics in Lung cancer Etiology.</p>a<p>Median (inter-quartile range).</p>b<p>“Non-educated” subjects are those who did not complete the elementary school.</p><p><b>Note:</b> Numbers of participants may not sum to total due to missing data.</p