The impact of climate change on crop mix shift in the Nordic region.

Growing evidence of anthropogenic climate change suggests marked changes in agricultural ecosystems and crop suitability across the globe. Northern Europe is primarily predicted to see beneficial impacts through crop shifts towards the North of the region. However, studies that quantify the magnitude of climate induced past shifts and the likely future shifts in the agricultural land use patterns are lacking. We use a rich municipality level longitudinal data set from the Nordic region from 1979 to 2012 to study farmers' adaptation to climate change in terms of crop mix shift. We model four land use classes, namely, cereal, grass, oil seed, and 'others', a category summing the remaining agricultural land uses. On top of climatic variables, we include biophysical and economic variables as controls in the regression. We utilize a multinomial fractional logit regression to estimate changes in the land use mix. The projection results indicate that both the near future (2041-2070) and the far future (2071-2100) projected climate are likely to increase the area share of cereal and at the same time decrease the share of grass in the Nordic region relative to the baseline climate (1981-2010). However, these results vary across the region. The results generally suggest a moderate climate induced impact on the spatial crop distributions. Our projection results show a moderate shift in agricultural crop distributions depending on the climate scenario and the time-horizon. Depending on the climate change scenario, grass and cereal are expected to shift by up to 92.8 and 178.7 km, respectively, towards opposite directions; grass towards the South-West and cereal towards the North-East. Overall, the projected areal expansion of cereal towards the North-East is expected to lead to increased environmental pressure.

Long-term residential exposure to air pollution and risk of testicular cancer in Denmark: A population-based case-control study.

BACKGROUND: The incidence rate risk of testicular cancer has increased over the last four decades, and most significant increase has been among Caucasian men in Nordic countries. Second-generation immigrant studies indicate a significant role of environmental exposure in testicular cancer. METHODS: We conducted a nationwide register-based case-control study, including 6,390 testicular cancer cases registered in the Danish Cancer Registry between 1989 and 2014. Up to four age-matched controls for each case (n=18,997) were randomly selected from Civil Registration System. Ambient air pollution levels were estimated at addresses of cases and controls with a state-of-the-art air pollution modeling system. RESULTS: We mostly found ORs close to 1.00 and with 95% confidence intervals (CI) spanning 1.00. Exposure during the year preceding birth was associated with ORs for NO2 of 0.87 (95%CI: 0.77-0.97) per 10 µg/m3 and for organic carbon of 0.84 (95%CI: 0.72-0.98) per 1 µg/m3. Exposure during the first 10 years of life was associated with ORs for organic carbon of 0.79 (95%CI: 0.67-0.93) per 1 µg/m3, for O3 of 1.20 (95%CI: 1.07-1.34) per 10 µg/m3 and for secondary inorganic aerosols of 1.07 (95%CI: 1.00-1.15) per 1 µg/m3. CONCLUSIONS: Early-life exposure to NO2 and OC was associated with lower risk for testicular cancer whereas early-life exposure to O3 and SIA was associated with higher risk. IMPACT: We report both positive and negative associations between ambient air pollutants and risk of testicular, dependent on pollutant, exposure time window and age at diagnosis. This is the first study to investigate such associations.

Influence of exposure assessment methods on associations between long-term exposure to outdoor fine particulate matter and risk of cancer in the French cohort Gazel.

BACKGROUND: Many studies investigated the relationship between outdoor fine particulate matter (PM2.5) and cancer. While they generally indicated positive associations, results have not been fully consistent, possibly because of the diversity of methods used to assess exposure. OBJECTIVES: To investigate how using different PM2.5 exposure assessment methods influences risk estimates in the large French general population-based Gazel cohort (20,625 participants at enrollment) with a 26-year follow-up with complete residential histories. METHODS: We focused on two cancer incidence outcomes: all-sites combined and lung. We used two distinct exposure assessment methods: a western European land use regression (LUR), and a chemistry-dispersion model (Gazel-Air) for France, each with a time series ≥20-years annual concentrations. Spearman correlation coefficient between the two estimates of PM2.5 was 0.71 across all person-years; the LUR tended to provide higher exposures. We used extended Cox models with attained age as time-scale and time-dependent cumulative exposures, adjusting for a set of confounders including sex and smoking, to derive hazard ratios (HRs) and their 95% confidence interval, implementing a 10-year lag between exposure and incidence/censoring. RESULTS: We obtained similar two-piece linear associations for all-sites cancer (3711 cases), with a first slope of HRs of 1.53 (1.24-1.88) and 1.43 (1.19-1.73) for one IQR increase of cumulative PM2.5 exposure for the LUR and the Gazel-Air models respectively, followed by a plateau at around 1.5 for both exposure assessments. For lung cancer (349 cases), the HRs from the two exposure models were less similar, with largely overlapping confidence limits. CONCLUSION: Our findings using long-term exposure estimates from two distinct exposure assessment methods corroborate the association between air pollution and cancer risk.

Long-term residential exposure to air pollution and Hodgkin lymphoma risk among adults in Denmark: a population-based case-control study.

PURPOSE: The etiology of Hodgkin lymphoma (HL) is obscure. Research on air pollution and risk of HL provides inconsistent results. We aimed to investigate the association between long-term residential exposure to air pollution and risk of adult Hodgkin lymphoma in Denmark. METHODS: We performed a nationwide register-based case-control study, including all (n = 2,681) Hodgkin lymphoma cases registered in the nationwide Danish Cancer Registry between 1989 and 2014. We randomly selected 8,853 age- and sex-matched controls from the entire Danish population using the Civil Registration System, and identified 20-year residential address history for all cases and controls. We modeled outdoor air pollution concentrations at all these addresses using the high-resolution multiscale air pollution model system DEHM/UBM/AirGIS. We used conditional logistic regression to estimate odds ratios adjusted for individual and neighborhood level sociodemographic variables. RESULTS: There was no association between 1, 5, 10, and 20 years' time-weighted average exposure to fine particles (PM2.5), O3, SO2, NO2, or the PM2.5 constituents OC, NH4, NO3, and SO4 and risk of Hodgkin lymphoma. CONCLUSION: Residential exposure to ambient air pollution does not seem to increase the risk of developing Hodgkin lymphoma.

Contribution of Long-Term Exposure to Outdoor Black Carbon to the Carcinogenicity of Air Pollution: Evidence regarding Risk of Cancer in the Gazel Cohort.

BACKGROUND: Black carbon (BC), a component of fine particulate matter [particles with an aerodynamic diameter ≤2.5 µm (PM2.5)], may contribute to carcinogenic effects of air pollution. Until recently however, there has been little evidence to evaluate this hypothesis. OBJECTIVE: This study aimed to estimate the associations between long-term exposure to BC and risk of cancer. This study was conducted within the French Gazel cohort of 20,625 subjects. METHODS: We assessed exposure to BC by linking subjects' histories of residential addresses to a map of European black carbon levels in 2010 with back- and forward-extrapolation between 1989 and 2015. We used extended Cox models, with attained age as time-scale and time-varying cumulative exposure to BC, adjusted for relevant sociodemographic and lifestyle variables. To consider latency between exposure and cancer diagnosis, we implemented a 10-y lag, and as a sensitivity analysis, a lag of 2 y. To isolate the effect of BC from that of total PM2.5, we regressed BC on PM2.5 and used the residuals as the exposure variable. RESULTS: During the 26-y follow-up period, there were 3,711 incident cancer cases (all sites combined) and 349 incident lung cancers. Median baseline exposure in 1989 was 2.65 10-5/m [interquartile range (IQR): 2.23-3.33], which generally slightly decreased over time. Using 10 y as a lag-time in our models, the adjusted hazard ratio per each IQR increase of the natural log-transformed cumulative BC was 1.17 (95% confidence interval: 1.06, 1.29) for all-sites cancer combined and 1.31 (0.93, 1.83) for lung cancer. Associations with BC residuals were also positive for both outcomes. Using 2 y as a lag-time, the results were similar. DISCUSSION: Our findings for a cohort of French adults suggest that BC may partly explain the association between PM2.5 and lung cancer. Additional studies are needed to confirm our results and further disentangle the effects of BC, total PM2.5, and other constituents. https://doi.org/10.1289/EHP8719.

Exposure to PM2.5 constituents and risk of adult leukemia in Denmark: A population-based case-control study.

BACKGROUND: Leukemia is one of the most common forms of hematologic malignancy, which can affect people of all ages. We previously showed an association between exposure to ambient particulate matter 2.5 µg (PM2.5) and risk for leukemia in adults. The aim of this study was to investigate which PM2.5 constituents were responsible for our previous observation. METHODS: This is a nationwide register-based case-control study. We identified 14,983 persons diagnosed with leukemia at age 20 or above, 1989-2014, in the Danish Cancer Registry. We selected up to four sex and age-matched controls per case at random from the entire Danish population (n = 51,613). We modelled concentrations of ambient PM2.5 and its constituents at the addresses of cases and controls for the 10-year period before index date with a state-of-the-art multiscale air pollution modeling system. We used conditional logistic regression to estimate odds ratios (ORs) adjusted for individual and neighborhood level socio-demographic variables. RESULT: The results showed higher risk for overall leukemia in association with interquartile range exposure to PM2.5 (OR = 1.09; 95% CI: 1.02, 1.17), black carbon (BC) (OR = 1.02; 95% CI: 1.00, 1.03), secondary inorganic aerosols (SIA) (OR = 1.15; 95% CI: 1.03, 1.29) and its components ammonium (NH4) (OR = 1.08; 95% CI: 1.00, 1.17) and nitrate (NO3) (OR = 1.08; 95% CI: 1.02, 1.14). In leukemia subtype analysis, statistically significant associations were found for AML with PM2.5 (OR = 1.14; 95% CI: 1.00, 1.29), BC (OR = 1.03; 95% CI: 1.00, 1.07), SIA (OR = 1.23; 95% CI: 1.01, 1.51), NH4 (OR = 1.16; 95% CI: 1.01, 1.34) and NO3 (OR = 1.12; 95% CI: 1.01, 1.24). The association between PM2.5 and leukemia persisted in two pollutants models including sum of primary emitted black and organic carbon (BC + OC), secondary organic aerosols (SOA), or sea-salt. The association between black carbon (BC) and leukemia persisted in two pollutants models including organic carbon (OC). The three pollutant model with sulfate (SO4), NH4 and NO3 showed an association with NO3 but not with SO4 or NH4. CONCLUSION: Ambient concentrations of the PM2.5 components BC, NH4 and NO3 at the residence showed associations with risk of incident leukemia in adults.

Air pollution exposure at the residence and risk of childhood cancers in Denmark: A nationwide register-based case-control study.

BACKGROUND: The etiology of childhood cancer is poorly understood. The role of environmental factors, including air pollution (AP) exposure, has been addressed previously, but results so far have been inconclusive. In this study, we investigate the association between long-term AP exposures in relation to childhood cancer subtypes in Denmark (1981-2013). METHODS: We conducted a nationwide register-based case-control study. We identified 7745 incident cases of childhood cancers (<20 years) in the Danish Cancer Registry. Four randomly selected (cancer-free) controls were matched to each case according to sex and date of birth. We modelled concentrations of nitrogen dioxide (NO2), fine particles (PM2·5), and black carbon (BC) at all addresses and calculated a time-weighted average from birth to index-date with a state-of-the-art multiscale AP modelling system. We analyzed the risk of childhood cancer in conditional logistic regression models adjusted for socio-demographic variables obtained from registers at the individual and neighborhood level. FINDINGS: The main analyses included 5045 cases and 18,179 controls. For all cancers combined, we observed odds ratios (ORs) and 95% confidence intervals (95% CI) of 0·97 (0·94, 1·01) per 10 µg/m3 NO2, 0·89 (0·82, 0·98) per 5 µg/m3 PM2·5, and 0·94 (0·88, 1·01) per 1 µg/m3 BC, respectively. Most notably, we observed a higher risk of Non-Hodgkin Lymphoma (NHL) with higher childhood AP exposure with ORs and 95% CIs of 1·21 (0·94, 1·55) per 10 µg/m3 NO2, 2·11 (1·10, 4·01) per 5 µg/m3 PM2·5, and 1·68 (1·06, 2·66) per 1 µg/m3 BC, respectively. We observed indications of increased risks for other types of childhood cancer, however, with very wide CIs including 1. INTERPRETATIONS: The findings of this nation-wide study propose a role of AP in the development of childhood NHL, but more large-scale studies are needed. FUNDING: NordForsk Project #75007.

Residential Exposure to PM2.5 Components and Risk of Childhood Non-Hodgkin Lymphoma in Denmark: A Nationwide Register-Based Case-Control Study.

In a recent study, we observed an increased risk of childhood non-Hodgkin lymphoma (NHL) associated with exposure to fine atmospheric particulate matter (PM2.5) and black carbon (BC). In this nationwide register-based case-control study, we focus on specific components of PM2.5 in relation to childhood NHL in Denmark (1981-2013) by identifying all incidents of childhood NHL cases in the Danish Cancer Registry (n = 170) and four (cancer-free) randomly selected controls matched by date of birth and sex. We applied PM2.5 concentrations and the following sub-components: secondary organic aerosols (SOA), secondary inorganic aerosols (SIA; i.e., NO3-, NH4+ and SO42-), BC, organic carbon (OC) and sea salt. We calculated a time-weighted exposure average from birth to index-date at all addresses. Odds ratios (ORs) were adjusted for register-based socio-demographic variables. We observed adjusted ORs and 95% confidence intervals (95% CI) of 2.05 (1.10, 3.83) per interquartile range (IQR, 4.83 µg/m3) PM2.5 and 1.73 (0.68, 4.41) per IQR (3.71 µg/m3) SIA, 0.95 (0.71, 1.29) per IQR (0.05 µg/m3) SOA, 1.22 (1.02, 1.46) per IQR (0.39 µg/m3) BC, 1.02 (0.83, 1.26) per IQR (0.56 µg/m3) OC and 1.01 (0.79, 1.30) per IQR (0.87 µg/m3) sea salt, respectively. The estimates were attenuated after adjustment for PM2.5, whereas the OR for PM2.5 remained increased regardless of adjustment for specific components. The findings indicate that the previously observed relation between PM2.5 and childhood NHL may be related to BC (as reported in our previous study) but also partly to SIA, but the role of specific chemical components of PM2.5 remains ambiguous.

Associations of Preconception Exposure to Air Pollution and Greenness with Offspring Asthma and Hay Fever.

We investigated if greenness and air pollution exposure in parents' childhood affect offspring asthma and hay fever, and if effects were mediated through parental asthma, pregnancy greenness/pollution exposure, and offspring exposure. We analysed 1106 parents with 1949 offspring (mean age 35 and 6) from the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) generation study. Mean particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), black carbon (BC), ozone (O3) (µg/m3) and greenness (normalized difference vegetation index (NDVI)) were calculated for parents 0-18 years old and offspring 0-10 years old, and were categorised in tertiles. We performed logistic regression and mediation analyses for two-pollutant models (clustered by family and centre, stratified by parental lines, and adjusted for grandparental asthma and education). Maternal medium PM2.5 and PM10 exposure was associated with higher offspring asthma risk (odds ratio (OR) 2.23, 95%CI 1.32-3.78, OR 2.27, 95%CI 1.36-3.80), and paternal high BC exposure with lower asthma risk (OR 0.31, 95%CI 0.11-0.87). Hay fever risk increased for offspring of fathers with medium O3 exposure (OR 4.15, 95%CI 1.28-13.50) and mothers with high PM10 exposure (OR 2.66, 95%CI 1.19-5.91). The effect of maternal PM10 exposure on offspring asthma was direct, while for hay fever, it was mediated through exposures in pregnancy and offspring's own exposures. Paternal O3 exposure had a direct effect on offspring hay fever. To conclude, parental exposure to air pollution appears to influence the risk of asthma and allergies in future offspring.

Long-term exposure to PM2.5 and its constituents and risk of Non-Hodgkin lymphoma in Denmark: A population-based case-control study.

BACKGROUND: Particulate matter (PM) air pollution is a complex mixture and the various PM constituents likely affect health differently. The literature on the relationships among specific PM constituents and the risk of cancer is sparse. In this study, we aimed to evaluate the association of PM2.5 and its constituents with the incidence of non-Hodgkin lymphoma (NHL) and the two main NHL subtypes. METHODS: We undertook a nationwide register-based case-control study including 20,847 cases registered in the Danish Cancer Registry with NHL between 1989 and 2014. Among the entire Danish population, we selected 41,749 age and sex-matched controls randomly from the Civil Registration System. We assessed modelled outdoor PM concentrations at addresses of cases and controls with a state-of-the-art multi scale air pollution modelling system and used conditional logistic regression to estimate odds ratios (ORs) adjusted for individual and neighborhood level socio-demographic variables. RESULTS: The 10-year time-weighted average concentrations of PM2.5, primary carbonaceous particles (BC/OC), secondary inorganic aerosols (SIA), secondary organic aerosols (SOA) and sea salt were 17.4, 2.3, 7.8, 0.3, and 4.1 µg/m3, respectively among controls. The results showed higher risk for NHL in association with exposure to BC/OC (OR = 1.03; 95% CI: 1.00, 1.07, per interquartile range (IQR)) and SOA (OR = 1.54; 95% CI: 1.13, 2.09, per IQR). The results indicated a higher risk for follicular lymphoma in association with several PM components. Including PM2.5 (OR = 1.16; 95% CI: 0.98-1.38), BC/OC (OR = 1.05; 95% CI: 0.97-1.14), SIA (OR = 1.44; 95% CI: 0.80-1.08), SOA (OR = 4.52; 95% CI: 0.86-23.83) per IQR. CONCLUSION: This is the first study on PM constituents and the risk of NHL. The results indicated an association with primary carbonaceous and secondary organic PM. The results need replication in other settings before any firm conclusion can be reached.

Long-term residential exposure to PM2.5 constituents and mortality in a Danish cohort.

Studies on health effects of long-term exposure to specific PM2.5 constituents are few. Previous studies have reported an association between black carbon (BC) exposure and cardiovascular diseases (CVD) and a few studies have found an association between sulfate exposure and mortality. These studies, however, relied mainly on exposure data from centrally located air-monitoring stations, which is a crude approximation of personal exposure. We focused on specific chemical constituents of PM2.5, i.e. elemental and primary organic carbonaceous particles (BC/OC), sea salt, secondary inorganic aerosols (SIA, i.e. NO3-, NH4+, and SO42-), and secondary organic aerosols (SOA), in relation to all-cause, CVD and respiratory disease mortality. We followed a Danish cohort of 49,564 individuals from enrollment in 1993-1997 through 2015. We combined residential address history from 1979 onwards with mean annual air pollution concentrations obtained by the AirGIS air pollution modelling system, lifestyle information from baseline questionnaires and socio-demography obtained by register linkage. During 895,897 person-years of follow-up, 10,193 deaths from all causes occurred - of which 2319 were CVD-related and 870 were related to respiratory disease. The 15-year time-weighted average concentrations of PM2.5, BC/OC, sea salt, SIA and SOA were 13.8, 2.8, 3.4, 4.9, and 0.3 µg/m3, respectively. For all-cause mortality, a higher risk was observed with higher exposure to PM2.5, BC/OC and SOA with adjusted hazard ratios of 1.03 (95% confidence intervals: 1.01, 1.05), 1.06 (1.03, 1.09), and 1.08 (1.03, 1.13) per interquartile range, respectively. The associations for BC/OC and SOA remained after adjustment for PM2.5 in two-pollutant models. For CVD mortality, we observed elevated risks with higher exposure to PM2.5, BC/OC and SIA. The results showed no clear relationship between sea salt and mortality. In this study, we observed a relationship between long-term exposure to PM2.5, BC/OC, and SOA and all-cause mortality and between PM2.5, BC/OC, and SIA and CVD mortality.

Influence of anthropogenic emissions and boundary conditions on multi-model simulations of major air pollutants over Europe and North America in the framework of AQMEII3.

In the framework of the third phase of the Air Quality Model Evaluation International Initiative (AQMEII3), and as contribution to the second phase of the Hemispheric Transport of Air Pollution (HTAP2) activities for Europe and North America, the impacts of a 20 % decrease of global and regional anthropogenic emissions on surface air pollutant levels in 2010 are simulated by an international community of regional-scale air quality modeling groups, using different state-of-the-art chemistry and transport models (CTMs). The emission perturbations at the global level, as well as over the HTAP2-defined regions of Europe, North America and East Asia, are first simulated by the global Composition Integrated Forecasting System (C-IFS) model from European Centre for Medium-Range Weather Forecasts (ECMWF), which provides boundary conditions to the various regional CTMs participating in AQMEII3. On top of the perturbed boundary conditions, the regional CTMs used the same set of perturbed emissions within the regional domain for the different perturbation scenarios that introduce a 20 % reduction of anthropogenic emissions globally as well as over the HTAP2-defined regions of Europe, North America and East Asia. Results show that the largest impacts over both domains are simulated in response to the global emission perturbation, mainly due to the impact of domestic emission reductions. The responses of NO2, SO2 and PM concentrations to a 20 % anthropogenic emission reduction are almost linear (~ 20 % decrease) within the global perturbation scenario with, however, large differences in the geographical distribution of the effect. NO2, CO and SO2 levels are strongly affected over the emission hot spots. O3 levels generally decrease in all scenarios by up to ~ 1 % over Europe, with increases over the hot spot regions, in particular in the Benelux region, by an increase up to ~ 6 % due to the reduced effect of NOx titration. O3 daily maximum of 8 h running average decreases in all scenarios over Europe, by up to ~ 1 %. Over the North American domain, the central-to-eastern part and the western coast of the US experience the largest response to emission perturbations. Similar but slightly smaller responses are found when domestic emissions are reduced. The impact of intercontinental transport is relatively small over both domains, however, still noticeable particularly close to the boundaries. The impact is noticeable up to a few percent, for the western parts of the North American domain in response to the emission reductions over East Asia. O3 daily maximum of 8 h running average decreases in all scenarios over north Europe by up to ~ 5 %. Much larger reductions are calculated over North America compared to Europe. In addition, values of the Response to Extra-Regional Emission Reductions (RERER) metric have been calculated in order to quantify the differences in the strengths of nonlocal source contributions to different species among the different models. We found large RERER values for O3 (~ 0.8) over both Europe and North America, indicating a large contribution from non-local sources, while for other pollutants including particles, low RERER values reflect a predominant control by local sources. A distinct seasonal variation in the local vs. non-local contributions has been found for both O3 and PM2.5, particularly reflecting the springtime long-range transport to both continents.

Assessment and economic valuation of air pollution impacts on human health over Europe and the United States as calculated by a multi-model ensemble in the framework of AQMEII3.

The impact of air pollution on human health and the associated external costs in Europe and the United States (US) for the year 2010 are modeled by a multi-model ensemble of regional models in the frame of the third phase of the Air Quality Modelling Evaluation International Initiative (AQMEII3). The modeled surface concentrations of O3, CO, SO2 and PM2.5 are used as input to the Economic Valuation of Air Pollution (EVA) system to calculate the resulting health impacts and the associated external costs from each individual model. Along with a base case simulation, additional runs were performed introducing 20 % anthropogenic emission reductions both globally and regionally in Europe, North America and east Asia, as defined by the second phase of the Task Force on Hemispheric Transport of Air Pollution (TF-HTAP2). Health impacts estimated by using concentration inputs from different chemistry-transport models (CTMs) to the EVA system can vary up to a factor of 3 in Europe (12 models) and the United States (3 models). In Europe, the multi-model mean total number of premature deaths (acute and chronic) is calculated to be 414 000, while in the US, it is estimated to be 160 000, in agreement with previous global and regional studies. The economic valuation of these health impacts is calculated to be EUR 300 billion and 145 billion in Europe and the US, respectively. A subset of models that produce the smallest error compared to the surface observations at each time step against an all-model mean ensemble results in increase of health impacts by up to 30 % in Europe, while in the US, the optimal ensemble mean led to a decrease in the calculated health impacts by ~ 11 %. A total of 54 000 and 27 500 premature deaths can be avoided by a 20 % reduction of global anthropogenic emissions in Europe and the US, respectively. A 20 % reduction of North American anthropogenic emissions avoids a total of ~ 1000 premature deaths in Europe and 25 000 total premature deaths in the US. A 20 % decrease of anthropogenic emissions within the European source region avoids a total of 47 000 premature deaths in Europe. Reducing the east Asian anthropogenic emissions by 20 % avoids ~ 2000 total premature deaths in the US. These results show that the domestic anthropogenic emissions make the largest impacts on premature deaths on a continental scale, while foreign sources make a minor contribution to adverse impacts of air pollution.