Occupational Risk Factors in Chronic Obstructive Pulmonary Disease

Introduction: Chronic obstructive pulmonary disease (COPD) causes increased disability and mortality in the U.S. population. Approximately 15% of cases of COPD can be attributed to occupational exposure. There are gaps in the knowledge of the relationships between occupational exposure and COPD and further investigation can provide information helpful in improving COPD preventive strategies in the workplace. The objective of this project was to assess COPD prevalence in population based studies and characterize the relationship between COPD and occupational exposure.;Methods/Results: Three separate U.S. population-based cross-sectional studies of COPD were conducted. In the first study, a COPD job exposure matrix (JEM) was created to characterize exposure of working adults to vapors-gas, dust, and fumes (VGDF). Next the JEM was applied to investigate the association between occupational exposure and COPD using data from a large population-based study where good quality spirometry and questionnaire data on chronic bronchitis, wheeze, and severity and duration of exposure to VGDF were collected. In the second study, COPD prevalence was estimated for the older U.S. population (40--79 years of age) over two periods, years 1988--1994 and years 2007--2010. The results show that COPD prevalence is declining. However, COPD still remains a significant problem. In the third study, prevalence estimates of COPD for the U.S. working population by major occupational groups were estimated. Higher odds of COPD were found among certain occupation groups.;Conclusions: The findings from this study provide perspective on contemporary trends in COPD prevalence and confirm that COPD remains a substantial problem in the U.S. population and more specifically in the working population. Exposure to VGDF continues to be associated with COPD as does smoking. This research expands the evidence on the association of COPD with VGDF exposure and certain occupation groups highlighting current trends in the U.S. occupations at risk for COPD. Understanding these evolving trends in COPD prevalence helps to develop strategies and interventions to further reduce exposure to VGDF and tobacco smoking to reduce the burden of COPD

Scientific outcomes and future challenges of the Ocean Carbon and Biogeochemistry Program

Author Posting. © The Oceanography Society, 2014. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 27, no. 1 (2014): 106–107, doi:10.5670/oceanog.2014.13.The ocean plays a major role in shaping Earth's climate, regulating levels of key atmospheric trace gases such as carbon dioxide on time scales of decades to millennia. Much progress has been made in understanding the global carbon cycle; quantifying major carbon sources, sinks, and transport pathways; and tracking the fate of anthropogenic carbon released from fossil fuel combustion and deforestation. However, many key questions remain regarding the magnitude and evolution of ocean uptake of anthropogenic carbon and the likely biogeochemical and ecosystem responses and feedbacks to future changes in ocean chemistry and climate

Correction to “Recent western South Atlantic bottom water warming”

Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 33 (2006): L21604, doi:10.1029/2006GL028294

How choice of depth horizon influences the estimated spatial patterns and global magnitude of ocean carbon export flux

Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 45 (2018): 4171-4179, doi:10.1029/2017GL076498.Estimated rates and efficiency of ocean carbon export flux are sensitive to differences in the depth horizons used to define export, which often vary across methodological approaches. We evaluate sinking particulate organic carbon (POC) flux rates and efficiency (e‐ratios) in a global earth system model, using a range of commonly used depth horizons: the seasonal mixed layer depth, the particle compensation depth, the base of the euphotic zone, a fixed depth horizon of 100 m, and the maximum annual mixed layer depth. Within this single dynamically consistent model framework, global POC flux rates vary by 30% and global e‐ratios by 21% across different depth horizon choices. Zonal variability in POC flux and e‐ratio also depends on the export depth horizon due to pronounced influence of deep winter mixing in subpolar regions. Efforts to reconcile conflicting estimates of export need to account for these systematic discrepancies created by differing depth horizon choices.Woods Hole Oceanographic Institution (WHOI); National Science Foundation Grant Number: OCE‐14340002018-10-2

Remote sensing observations of ocean physical and biological properties in the region of the Southern Ocean Iron Experiment (SOFeX)

Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 111 (2006): C06026, doi:10.1029/2005JC003289.Satellite remote sensing estimates of surface chlorophyll, temperature, wind speed, and sea ice cover are examined in the region of the Southern Ocean Iron Experiment (SOFeX). Our objectives are to place SOFeX into a regional context and highlight regional mesoscale spatial and monthly temporal variability. SOFeX fertilized two patches with iron, one south of the Antarctic Polar front (PF) and one north of the PF but south of the Subantarctic Front (SAF). Satellite observable phytoplankton blooms developed in both patches. The spring sea-ice retreat near the south patch site was delayed in the 2001-2002 season, in turn delaying the naturally occurring, modest spring bloom in this region. Ambient surface chlorophyll concentrations for the area surrounding the southern patch during January 2002 are low (mean 0.26 mg/m3) compared with climatological January values (0.42 mg/m3). Regions east and west at similar latitudes exhibited higher mean chlorophyll concentrations (0.79 and 0.74 mg/m3, respectively). These modest phytoplankton blooms were likely stimulated by melting sea-ice via changes in the light-mixing regime and release of iron, and were smaller in magnitude than the iron-induced bloom within the SOFeX southern patch (> 3 mg/m3). Iron inputs from melting ice may drive much of the natural spatial and temporal variability within the seasonal ice zone. Mean chlorophyll concentrations surrounding the SOFeX northern patch site were similar to climatological values during the SOFeX season. The northern patch was stretched into a long, thin filament along the southern boundary of the SAF, likely increasing the mixing/dilution rate with surrounding waters.S. Doney and K. Moore were supported by NASA grant NAG5-12520 from the NASA Ocean Biogeochemistry Program

Oceanography : oxygen and climate dynamics

Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Climate Change 4 (2014): 862-863, doi:10.1038/nclimate2386.Low oxygen levels in tropical oceans shape marine ecosystems and biogeochemistry with climate change expected to expand these regions. Now, a study indicates that regional dynamics control tropical oxygen trends, bucking projected global reductions in ocean oxygen.2015-03-2

When an ecological regime shift is really just stochastic noise

Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 110 (2013): 2438–2439, doi:10.1073/pnas.1222736110.Populations of marine species wax and wane over time and space reflecting environmental forcing, biological dynamics, and in some cases human perturbations such as fishing, habitat destruction and climate change. The growing availability of multi‐decadal observational records opens new windows on how ocean ecosystems function, but the analysis and interpretation of such long time-­‐series also requires new mathematical tools and conceptual models. Population time-­‐ series often show strong variations at decadal time‐scales, and a central question is whether this arises from non‐linear biological processes or simply tracking of external physical variability. Borrowing from climate research, Di Lorenzo and Ohman develop a novel approach for deciphering links between physical forcing and biological response, using as a test case time‐series of marine zooplankton abundances off the coast of California.The authors gratefully acknowledge support from the U.S. National Science Foundation through the Palmer Long Term Ecological Research (LTER) project (http://pal.lternet.edu/) (NSF OPP-­‐0823101)

The effect of boundary conditions on tracer estimates of thermocline ventilation rates

Using a simple box mixing model, we show that ventilation rate estimates obtained from tracer box models may be significantly smaller than fluid replacement rates. The degree to which a tracer ventilation estimate approaches the actual (fluid) ventilation rate depends on the surface boundary condition for that tracer. Ventilation rates for rapidly exchanging tracers (e.g. 3He) are close to the fluid ventilation rate while tracers with limited surface exchange (e.g. tritium) ventilate more slowly. For box mixing models, the ratio of ventilation rates for limited surface exchange tracers to rapidly exchanging tracers approaches the ratio of summer to winter mixed layer depths. Further, the distribution of rapidly equilibrating tracers more accurately tracks climatological fluctuations in water mass formation rates. Limited surface exchange tracers show a damping proportional to the ratio of summer to winter mixed layer depths. To compare model results with observations, we calculate 3He and tritium ventilation rates from data taken in 1979 in the eastern subtropical North Atlantic. In calculating the tritium ventilation rates, we modify a North Atlantic tritium “source function” (time history of-surface water tritium concentrations), extending previous work using recent data. On shallow density surfaces (σ \u3c 27.0), the computed tritium ventilation rates are 2–3 times slower than those for 3He, in agreement with climatological ratio of summer to winter mixed layer depths. Deeper in the thermocline, the two tracer estimated ventilation rates converge. This trend may be related to the decreasing effectiveness of 3He gas exchange in equilibrating the deeper winter mixed layers of the more northerly isopycnal outcrops. We conclude that box models using limited surface exchange tracers (e.g. 14C and tritium) can under predict oxygen utilization rates (OUR) by up to 3 times due to differences in tracer boundary conditions, while a tracer like 3He may overestimate OUR by 10–20%

A three-dimensional, multinutrient, and size-structured ecosystem model for the North Atlantic

Author Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 18 (2004): GB3019, doi:10.1029/2003GB002146.We incorporate multinutrient and size-structured ecosystem dynamics into a three-dimensional ocean general circulation model for the North Atlantic. The model reproduces the magnitude and general spatial and temporal patterns in nutrients, chlorophyll and primary production seen in in situ (BATS, NABE, and OWSI) and satellite (SeaWiFS) data, showing substantial improvements over prior basin-scale simulations. Model skill is evaluated quantitatively against SeaWiFS data using a Taylor diagram approach. Model-data correlation R for the overall surface chlorophyll time-space distribution is ∼0.6, with comparable model and observed total variability. The agreement relative to satellite-based primary production is somewhat weaker (0.2 < R < 0.5). The simulations capture observed ecological characteristics, e.g., the dominance of picoplankton and episodic diatom blooms in the subtropics, nutrient-controlled plankton succession at higher latitudes, and associated seasonal/depth changes in new and regenerated production and particle export. In a sensitivity experiment that mimics behavior of simpler single-species models, removal of diatom silica limitation leads to major shifts in community structure and export and larger model-data errors similar to previous model studies. Model results also suggest that episodic diatom blooms at BATS may be related to interannual variations in the southward transport of nutrients, mainly SiO3, and plankton cells.Support for this work was provided by NASA SeaWiFS grant W-19,223 and NSF JGOFS SMP grant 0222033

Anticipating ocean acidification's economic consequences for commercial fisheries

Author Posting. © IOP Publishing, 2009. This is the author's version of the work. It is posted here by permission of IOP Publishing for personal use, not for redistribution. The definitive version was published in Environmental Research Letters 4 (2009): 024007, doi:10.1088/1748-9326/4/2/024007.Ocean acidification, a consequence of rising anthropogenic CO2 emissions, is poised to change marine ecosystems profoundly by increasing dissolved CO2 and decreasing ocean pH, carbonate concentration, and calcium carbonate mineral saturation state worldwide. These conditions hinder growth of calcium carbonate shells and skeletons by many marine plants and animals. The first direct impact on humans may be through declining harvests and fishery revenues from shellfish, their predators, and coral reef habitats. In a case study of U.S. commercial fishery revenues, we begin to constrain the economic effects of ocean acidification over the next 50 years using atmospheric CO2 trajectories and laboratory studies of its effects, focusing especially on mollusks. In 2007, the $3.8 billion U.S. annual domestic ex-vessel commercial harvest ultimately contributed$34 billion to the U.S. gross national product. Mollusks contributed 19%, or $748 million, of the ex-vessel revenues that year. Substantial revenue declines, job losses, and indirect economic costs may occur if ocean acidification broadly damages marine habitats, alters marine resource availability, and disrupts other ecosystem services. We review the implications for marine resource management and propose possible adaptation strategies designed to support fisheries and marine-resource-dependent communities, many of which already possess little economic resilience.This work was supported by NASA grant NNG05GG30G and a generous grant from the WHOI Development Office