Is long-term particulate matter and nitrogen dioxide air pollution associated with incident monoclonal gammopathy of undetermined significance (MGUS)? An analysis of the Heinz Nixdorf Recall study

Long-term exposure to ambient air pollution and risk of leukemia and lymphoma in a pooled European cohort

Leukemia and lymphoma are the two most common forms of hematologic malignancy, and their etiology is largely unknown. Pathophysiological mechanisms suggest a possible association with air pollution, but little empirical evidence is available. We aimed to investigate the association between long-term residential exposure to outdoor air pollution and risk of leukemia and lymphoma. We pooled data from four cohorts from three European countries as part of the "Effects of Low-level Air Pollution: a Study in Europe" (ELAPSE) collaboration. We used Europe-wide land use regression models to assess annual mean concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO2), black carbon (BC) and ozone (O3) at residences. We also estimated concentrations of PM2.5 elemental components: copper (Cu), iron (Fe), zinc (Zn); sulfur (S); nickel (Ni), vanadium (V), silicon (Si) and potassium (K). We applied Cox proportional hazards models to investigate the associations. Among the study population of 247,436 individuals, 760 leukemia and 1122 lymphoma cases were diagnosed during 4,656,140 person-years of follow-up. The results showed a leukemia hazard ratio (HR) of 1.13 (95% confidence intervals [CI]: 1.01-1.26) per 10 μg/m3 NO2, which was robust in two-pollutant models and consistent across the four cohorts and according to smoking status. Sex-specific analyses suggested that this association was confined to the male population. Further, the results showed increased lymphoma HRs for PM2.5 (HR = 1.16; 95% CI: 1.02-1.34) and potassium content of PM2.5, which were consistent in two-pollutant models and according to sex. Our results suggest that air pollution at the residence may be associated with adult leukemia and lymphoma.

Multiple myeloma risk in relation to long-term air pollution exposure - A pooled analysis of four European cohorts

BACKGROUND

Air pollution is a growing concern worldwide, with significant impacts on human health. Multiple myeloma is a type of blood cancer with increasing incidence. Studies have linked air pollution exposure to various types of cancer, including leukemia and lymphoma, however, the relationship with multiple myeloma incidence has not been extensively investigated.

METHODS

We pooled four European cohorts (N = 234,803) and assessed the association between residential exposure to nitrogen dioxide (NO2), fine particles (PM2.5), black carbon (BC), and ozone (O3) and multiple myeloma. We applied Cox proportional hazards models adjusting for potential confounders at the individual and area-level.

RESULTS

During 4,415,817 person-years of follow-up (average 18.8 years), we observed 404 cases of multiple myeloma. The results of the fully adjusted linear analyses showed hazard ratios (95% confidence interval) of 0.99 (0.84, 1.16) per 10 μg/m³ NO2, 1.04 (0.82, 1.33) per 5 μg/m³ PM2.5, 0.99 (0.84, 1.18) per 0.5 10-5 m-1 BCE, and 1.11 (0.87, 1.41) per 10 μg/m³ O3.

CONCLUSIONS

We did not observe an association between long-term ambient air pollution exposure and incidence of multiple myeloma.

Emerging role of mitochondria in airborne particulate matter-induced immunotoxicity

The immune system is one of the primary targets of airborne particulate matter. Recent evidence suggests that mitochondria lie at the center of particulate matter-induced immunotoxicity. Particulate matter can directly interact with mitochondrial components (proteins, lipids, and nucleic acids) and impairs the vital mitochondrial processes including redox mechanisms, fusion-fission, autophagy, and metabolic pathways. These disturbances impede different mitochondrial functions including ATP production, which acts as an important platform to regulate immunity and inflammatory responses. Moreover, the mitochondrial DNA released into the cytosol or in the extracellular milieu acts as a danger-associated molecular pattern and triggers the signaling pathways, involving cGAS-STING, TLR9, and NLRP3. In the present review, we discuss the emerging role of mitochondria in airborne particulate matter-induced immunotoxicity and its myriad biological consequences in health and disease.

Long-term exposure to ambient source-specific particulate matter and its components and incidence of cardiovascular events - The Heinz Nixdorf Recall study

BACKGROUND

Few studies have examined the risk of long-term exposure to source-specific airborne pollutants on incidence of cerebrovascular and cardiovascular events.

OBJECTIVES

We aimed to estimate the effect of long-term exposure to source-specific air pollution and particulate matter (PM) components on incidence of stroke, coronary heart disease (CHD), and total cardiovascular events (CVE) in the population-based Heinz Nixdorf Recall study (HNR).

METHODS

We used baseline (2000-2003) and 14-year follow-up data of the HNR Study, an ongoing population-based prospective cohort study in Western Germany. Participants' residential mean exposures to NO₂ and total and source-specific PM₁₀, PM_2.5, accumulation mode particle number concentration (PN_AM), and PM components were modelled using a dispersion and chemical transport model. We used Cox regression to evaluate the effect of pollutants (per 1 μg/m³ increase and per interquartile range - IQR) on risk of stroke and CHD, adjusting for socio-demographic characteristics, lifestyle risk factors and nighttime traffic noise exposure.

RESULTS

In 4,105 included participants (aged 45-76 at baseline, 52.5% women), we observed 118 cases of first stroke and 373 cases of first CHD during 46,748 person-years under risk. The median survival time within the cohort was 13.3 years. No effect of exposure to ambient air pollution on risk of CHD was observed, but distinct effects were observed for stroke. Ambient traffic-specific PM showed a stronger effect on stroke than industry-specific PM: hazard ratios (95% confidence interval) for total, traffic-specific, and industry-specific PM_2.5 were 1.16 (1.02-1.34), 2.53 (1.07-5.97), and 1.27 (1.03-1.56) per 1 μg/m³ increase, respectively. PM components showed no substantially different effects from those of total PM per IQR, but higher associations were observed for NH₄ and SO₄ per 1 μg/m³. However, the exposure contrast of ammonium and sulfate components was very low.

CONCLUSION

Traffic-specific PM exhibited stronger effects than total and industry-specific PM on risk of stroke. Among components, NH₄ and SO₄ showed higher effects. No effect was observed for PM and CHD.

Characteristics of cohort studies of long-term exposure to PM2.5: a systematic review

This study systematically reviewed all the cohort studies investigating the relationship between long-term exposure to PM_2.5 and any health outcome until February 2018. We searched ISI Web of Knowledge, Pubmed, and Scopus databases for peer-reviewed journal research articles published in English. We only extracted the results of the single-pollutant main analysis of each study, excluding the effect modifications and sensitivity analyses. Out of the initial 9523 articles, 203 articles were ultimately included for analysis. Based on the different characteristics of studies such as study design, outcome, exposure assessment method, and statistical model, we calculated the number and relative frequency of analyses with statistically significant and insignificant results. Most of the studies were prospective (84.8%), assessed both genders (66.5%), and focused on a specific age range (86.8%). Most of the articles (78.1%) had used modeling techniques for exposure assessment of cohorts' participants. Among the total of 317 health outcomes, the most investigated outcomes include mortality due to cardiovascular disease (6.19%), all causes (5.48%), lung cancer (4.00%), ischemic heart disease (3.50%), and non-accidental causes (3.50%). The percentage of analyses with statistically significant results were higher among studies that used prospective design, mortality as the outcome, fixed stations as exposure assessment method, hazard ratio as risk measure, and no covariate adjustment. We can somehow conclude that the choice of right characteristics for cohort studies can make a difference in their results.

Monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant plasma cell dyscrasia that consistently precedes multiple myeloma (MM) with a 1% risk of progression per year. Recent advances have improved understanding of the complex genetic and immunologic factors that permit progression from the aberrant plasma cell clone to MGUS and overt MM. Additional evidence supports bidirectional interaction of MGUS cells with surrounding cells in the bone marrow niche that regulates malignant transformation. However, there are no robust prognostic biomarkers. Herein we review the current body of literature on the biology of MGUS and provide a rationale for the improved identification of high-risk MGUS patients who may be appropriate for novel clinical interventions to prevent progression or eradicate premalignant clones prior to the development of overt MM.

[Epidemiological studies with environmental relevance in Germany]

Our environment is a major factor in determining health and well-being throughout life, from conception into old age. This overview illustrates the most important epidemiological studies and health monitoring systems in Germany, which investigate environmental influences in various population subgroups and estimate related health effects. Environmental factors examined in each study are described. The mentioned studies in children and adults build the basis for predictions and preventive measures. The number of the assessed environmental factors, the depth of the examinations as well as the (phenotypical) characterization of the study participants differ. Still, the obtained data build a base for important future research. However, for this, a permanent and Germany-wide assessment of environmental factors is necessary.The proportion of the European population living in urban areas is projected to increase in the future. Therefore, environmental factors such as air pollution, air temperature, and noise, but also social inequality, are likely to have a negative effect on health and quality of life of the population. The challenge of the aging population as well as potential adaptation processes to the diverse environmental stimuli requires multidisciplinary approaches. From an environmental epidemiology view, the collected data from the described studies are of immense value because only with this data can associations between environment and health be investigated and public health-relevant preventive measures be identified.The NAKO health study will be the largest resource of health data and should therefore be included in future activities related to the investigation of environmental health effects in Germany.