Effects of SO2 plus NaCl aerosol combined with moderate exercise on pulmonary function in asthmatic adolescents

Eight adolescent subjects with a diagnosis of extrinsic asthma and exercise-induced bronchospasm were exposed for 30 min at rest followed by 10 min of moderate exercise on a treadmill to the following experimental modes: (a) filtered air, (b) 1 ppm of sulfur dioxide (SO₂) and 1 mg/m³ of sodium chloride (NaCl) droplet aerosol, or (c) 1 mg/m³ of NaCl droplet aerosol alone. All exposures were at ?75% relative humidity and 22°C. Functional measurements of total respiratory resistance (R_T), maximal flow at 50 and 75% expired vital capacity ($\text{V}\text{?}{}_{\mathrm{<mtext>max</mtext><mtext>50</mtext>}}$ and $\text{V}\text{?}{}_{\mathrm{<mtext>max</mtext><mtext>75</mtext>}}$), forced expiratory volume in 1 sec (FEV_1.0), and functional residual capacity (FRC) were recorded before and after exposure. Statistically significant changes were seen in R_T, $\text{V}\text{?}{}_{\mathrm{<mtext>max</mtext><mtext>50</mtext>}}$ and $\text{V}\text{?}{}_{\mathrm{<mtext>max</mtext><mtext>75</mtext>}}$, and FEV_1.0 following exposure to SO₂  NaCl droplet aerosol during exercise. The changes seen were greater than those seen in the same subjects during exposure at rest or in healthy adult subjects exposed to various air pollutants.     

Acute effects of inhaled SO2 plus NaCl droplet aerosol on pulmonary function in asthmatic adolescents

Nine adolescent subjects with a diagnosis of extrinsic asthma were exposed at rest for 60 min to the following experimental modes: (a) filtered air; (b) 1 ppm of sulfur dioxide (SO₂) and 1 mg/m³ of sodium chloride (NaCl) droplet aerosol; c 1 mg/m³ of NaCl droplet aerosol alone. All exposures were at 75% relative humidity and 22°C temperature. Functional measurements of total respiratory resistance (R_T), maximal flow at 50 and 75% of expired vital capacity ($\text{V}\text{\_.}{}_{\mathrm{<mtext>max50</mtext>}}$ and $\text{V}\text{\_.}{}_{\mathrm{<mtext>max75</mtext>}}$), forced expiratory volume in 1 sec (FEV_1.0) and functional residual capacity (FRC) were recorded before, during, and after exposures. Significant decreases in $\text{V}\text{\_.}{}_{\mathrm{<mtext>max50</mtext>}}$ and $\text{V}\text{\_.}{}_{\mathrm{<mtext>max75</mtext>}}$ were seen when the group was exposed to the SO₂ plus NaCl droplet aerosol. No significant changes were seen during exposure to filtered air or NaCl droplet aerosol alone. The results suggest that the site of effect of the SO₂NaCl droplet aerosol was in small airways. The asthmatic adolescents appeared to be more sensitive to the SO₂ droplet aerosol than were healthy nonsmoking adults previously studied.     

Plasma levels and pharmacokinetics of norethindrone and ethinylestradiol administered in solution and as tablets to women

Twenty-four normal adult female volunteers were dosed orally with a solution and tablet formulation containing the contraceptive combination of norethindrone (NET, 1.0 mg) and ethinylestradiol (EE₂, 0.12 mg) in a crossover bioequivalence study. Blood was sampled sequentially following single oral doses and the plasma separated for analysis of NET and EE₂ by specific radioimmunoassays. Comparisons of both drugs following a dose in solution and tablets were made with respect to the following parameters: (a) plasma concentrations at each sample time; (b) maximum plasma concentration (Cp_max); (c) time to maximum plasma concentration (T_max); (d) total area under the plasma concentration vs. time curve (AUC), and (e) plasma half-life ($\text{t}\text{1}\text{2}$). It was found that the tablet and solution doses were bioequivalent with respect to EE₂ absorption. However, absorption of NET from solution and tablet doses exhibited significant differences with respect to plasma levels at certain time points as well as AUC (which were higher following the tablet dose), but Cp_max, T_max and $\text{t}\text{1}\text{2}$ were not significantly different. Pharmacokinetic analysis of both drugs following the tablet dose was carried out using a two-compartment open model. The absorption rate constant (k_a) and peripheral to central compartment transfer rate constant (k₂₁) were similar for NET and EE₂, but statistically significant differences were observed with respect to the distribution rate constant (α), the central to peripheral transfer rate constant (k₁₂), the overall elimination rate constant (k_el), and volume or distribution ($\text{V}{}_1\text{F}$). The elimination rate constant (β) for both drugs showed a difference of borderline statistical significance.     

The disposition of p-nitroanisole by the sea urchin, Strongylocentrotus purpuratusI. Kinetics

Investigation of the disposition kinetics of p-nitroanisole (PNA) by the sea urchin, Strongylocentrotus purpuratus, demonstrated the usefulness of our proposed protocol for assessing the disposition of xenobiotics in aquatic species. The protocol consists of four steps: toxicity rangefinding, acute static, dynamic (flowing water) and steady-state investigations of xenobiotic metabolism, and kinetics. Elimination kinetics from acute static investigations fit the form $\text{dQ}{}_{\mathrm{<mtext>w</mtext>}}\text{dt}\text{= K}{}_1\text{Q}{}_{\mathrm{<mtext>a</mtext>}}\text{? K}{}_2\text{Q}{}_{\mathrm{<mtext>w</mtext>}}$, where Q_w is the quantity of compound in the water, Q_a the quantity in the animal, K₁ the elimination rate constant, and K₂ the uptake rate constant. Estimates of the elimination and uptake rate constants were 0.57 ± 0.23 and 0.09 ± 0.05 hr^?1 (n = 32), respectively, for studies covering 1.5 years. A simpler method for estimating these rate constants is described. The elimination halflife was dependent on time held after collection and season, corresponding to the reproductive cycle. Steady-state studies indicated that the elimination of PNA is an active process. The turnover rate constant (1.3 ± 0.6 hr^?1) was not different from the acute elimination rate constant. Overall the rapid elimination of PNA and the rapid approach to steady state (approximately 8 hr) will be the prime factors in the fate of PNA in sea urchins. For short-term exposure, upon termination the sea urchin will rapidly and actively eliminate the compound. For chronic, long-term exposures, the sea urchin will rapidly achieve steady state and the fate will be dependent upon biotransformation.     

Absorption of carbaryl from the lung and small intestine of the rat

To investigate the pulmonary and intestinal absorption of the insecticide carbaryl (1-naphthyl-N-methylcarbamate; Sevin), solutions of the compound (0.005–0.1 mm) were administered into the lungs or small intestine of anesthetized rats. After various times, the organs were removed and assayed for compound that remained. Percentage of the dose unabsorbed was plotted semilogarithmically against time, and absorption half-times ($\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$) were calculated from the resulting curves. Results indicated that carbaryl was absorbed from the lungs ($\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 2.6}\text{min}$) 2.5 times faster than from the small intestine ($\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 6.4}\text{min}$). In addition, pulmonary and intestinal absorption of the insecticide appeared to occur by a nonsaturable process such as diffusion, since the amount of compound absorbed per unit time was directly proportional to the administered concentration.     

Responses of exercising subjects to acute "passive" cigarette smoke exposure.

Responses to 2 hr of “passive” cigarette smoke exposure have been tested in 23 healthy young men and women who were performing intermittent bicycle ergometer work sufficient to increase respiratory minute volumes by a factor of 2.5. A simple crossover design compared data with reactions to sham exposures of similar duration. Cigarettes were smoked by a standard machine; chamber carbon monoxide concentrations were 20 (moderate dose) or 31 ppm (heavy exposure). Symptoms were much as in moderate exposures without exercise. The main complaints were of odor and eye irritation. Cough, nasal discharge or stuffiness, and throat irritation were also reported, but wheezing, shortness of breath, and tightness in the chest were both uncommon and unsupported by objective evidence of bronchospasm. A small increase of tidal volume and respiratory minute volume seemed due to anxiety rather than airway irritation. Static lung volumes were unchanged, but there were small (3–4%) decreases of FVC, FEV_1.0', $\text{V}\text{?}{}_{\mathrm{<mtext>max</mtext><mtext>\; 50\%</mtext>}}$, and $\text{V}\text{?}{}_{\mathrm{<mtext>max</mtext><mtext>\; 25\%</mtext>}}$. The changes of dynamic lung volumes were of the order anticipated from the “cigarette equivalent” encountered by the passive smoker ($\text{<}\text{1}\text{2}$ cigarette in 2 hr).     

Comparison of spirometry performed on the same subjects by two teams using similar instruments: An investigation of variability in prevalence of impairment

To investigate variability in results of spirometric testing, spirometry was performed with similar automated equipment by two independently trained teams employing their customary procedures in 181 asbestos insulation workers. Results were analyzed for forced vital capacity (FVC), forced expiratory volume ? 1 sec (FEV₁), $\text{FEV}{}_1\text{FVC}$, and forced expiratory flow (FEF)_25–75. Differences > 10% were found for FVC in 31 workers (17%), for FEV₁ in 36 workers (20%), and for FEF_27–75 in 110 workers (61%). Prevalence of impairment as conventionally defined varied considerably, e.g., 13% decreased FVC vs 22% and 40% decreased $\text{FEV}{}_1\text{FVC}$ vs 30%. Variability in results was related to failure to monitor subject effort by recording a flow-volume or volume-time curve and failure to calibrate the instrument physically. External calibration of automated equipment and monitoring of subject effort by inscribed curves are essential for pulmonary function testing in epidemiologic surveys. Standardization of techniques must include these procedures. Otherwise the value of these investigations will be limited.     

Effect of cupric chloride on oxidative metabolism in the freshwater teleost, Tilapia mossambica

The freshwater teleost Tilapia mossambica was subjected to lethal ($\text{6.0 mg · liter}{}^{\mathrm{?1}}\text{=}\text{LC}{}_{50}\text{48}\text{hr}$) and sublethal (1.5 mg · liter^?1 copper treatment for 1, 7, and 14 days. The whole animal oxygen consumption and the activity levels of succinate dehydrogenase and lactate dehydrogenase in liver and muscle were studied. The decrease in oxygen consumption and succinate dehydrogenase activity and significant increase in lactate dehydrogenase activity suggest that the stressed fish is meeting its energy requirements through anaerobic oxidation and these enzymes can be used as indicators in monitoring metal-induced toxicity in fish.     

Prenatal Exposure to Air Pollution and Autism Spectrum Disorder: Sensitive Windows of Exposure and Sex Differences

Background: Studies have shown that air pollution exposures during pregnancy are associated with an increased risk of autism spectrum disorder (ASD) in children, and the risk appears to be greater for boys. However, studies assessing gestational windows of susceptibility have been mostly limited by trimesters.Objective: We identified sensitive windows of exposure to regional air pollution and risk of ASD and examined sex differences in a large birth cohort.Methods: This population-based retrospective cohort study included 294,937 mother–child pairs with singleton deliveries in Kaiser Permanente Southern California (KPSC) hospitals from 2001 to 2014. Children were followed using electronic medical records until clinical ASD diagnosis, non-KPSC membership, death, or 31 December 2019, whichever came first. Weekly mean fine particulate matter [PM with an aerodynamic diameter of ≤2.5μm (PM2.5)], nitrogen dioxide (NO2), and ozone (O3) pregnancy exposures were estimated using spatiotemporal prediction models. Cox proportional hazard models with distributed lags were used to estimate weekly pollutant exposure associations with ASD risk for the entire cohort, and separately for boys and for girls. Models were adjusted for child sex (for full cohort), maternal race/ethnicity, maternal age at delivery, parity, maternal education, maternal comorbidities, medical center, census tract median household income, birth year, and season.Results: There were 5,694 ASD diagnoses (4,636 boys, 1,058 girls). Sensitive PM2.5 exposure windows associated with ASD were found early in pregnancy, statistically significant throughout the first two trimesters [1–27 wk of gestation, cumulative hazard ratio (HR)=1.14 [95% confidence interval (CI): 1.06, 1.23] per interquartile range (IQR) (7.4-μg/m3) increase]. O3 exposure during 34–37 wk of gestation was associated with increased risk [HR=1.06 (95% CI: 1.01, 1.11) per IQR (17.4 ppb) increase] but with reduced risk during 20–28 wk of gestation [HR=0.93 (95% CI: 0.89, 0.98)]. No associations were observed with NO2. Sex-stratified early gestational PM2.5 associations were stronger among boys [boys HR=1.16 (95% CI: 1.08, 1.26); girls HR=1.06 (95% CI: 0.89, 1.26)]. O3 associations in later gestation were observed only in boys [boys HR=1.10 (95% CI: 1.04, 1.16); girls HR=0.94 (95% CI: 0.84, 1.05)].Conclusions: Exposures to PM2.5 in the first two gestational trimesters were associated with increased ASD risk in children, with stronger associations observed for boys. The role of O3 exposure on ASD risk merits further investigation. https://doi.org/10.1289/EHP9509     

Long-Term Exposures to Air Pollution and the Risk of Atrial Fibrillation in the Women’s Health Initiative Cohort

Background: Atrial fibrillation (AF) is associated with substantial morbidity and mortality. Short-term exposures to air pollution have been associated with AF triggering; less is known regarding associations between long-term air pollution exposures and AF incidence.Objectives: Our objective was to assess the association between long-term exposures to air pollution and distance to road on incidence of AF in a cohort of U.S. women.Methods: We assessed the association of high resolution spatiotemporal model predictions of long-term exposures to particulate matter (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), and distance to major roads with incidence of AF diagnosis, identified through Medicare linkage, among 83,117 women in the prospective Women’s Health Initiative cohort, followed from enrollment in Medicare through December 2012, incidence of AF, or death. Using time-varying Cox proportional hazards models adjusted for age, race/ethnicity, study component, body mass index, physical activity, menopausal hormone therapy, smoking, diet quality, alcohol consumption, educational attainment, and neighborhood socioeconomic status, we estimated the relative risk of incident AF in association with each pollutant.Results: A total of 16,348 incident AF cases were observed over 660,236 person-years of follow-up. Most exposure–response associations were nonlinear. NO2 was associated with risk of AF in multivariable adjusted models [Hazard Ratio (HR)=1.18; 95% confidence interval (CI): 1.13, 1.24, comparing the top to bottom quartile, p-for-trend=<0.0001]. Women living closer to roadways were at higher risk of AF (e.g., HR=1.07; 95% CI: 1.01, 1.13 for living within 50m of A3 roads, compared with ≥1,000 m, p-for-trend=0.02), but we did not observe adverse associations with exposures to PM10, PM2.5, or SO2. There were adverse associations with PM10 (top quartile HR=1.10; 95% CI: 1.05, 1.16, p-for-trend=<0.0001) and PM2.5 (top quartile HR=1.09; 95% CI: 1.03, 1.14, p-for-trend=0.002) in sensitivity models adjusting for census region.Discussion: In this study of postmenopausal women, NO2 and distance to road were consistently associated with higher risk of AF. https://doi.org/10.1289/EHP7683     

Folic Acid Supplementation and the Association between Maternal Airborne Particulate Matter Exposure and Preterm Delivery: A National Birth Cohort Study in China

Background: Potential modification of the association between maternal particulate matter (PM) exposure and preterm delivery (PTD) by folic acid (FA) supplementation has not been studied.Objective: We examined whether FA supplementation could reduce the risk of PTD associated with maternal exposure to PM in ambient air during pregnancy.Method: In a cohort study covering 30 of the 31 provinces of mainland China in 2014, 1,229,556 primiparas of Han ethnicity were followed until labor. We collected information on their FA supplementation and pregnancy outcomes and estimated each participant’s exposure to PM with diameters of ≤10μm (PM10), 2.5μm (PM2.5), and 1μm (PM1) using satellite remote-sensing based models. Cox proportional hazard regression models were used to examine interactions between FA supplementation and PM exposures, after controlling for individual characteristics.Results: Participants who initiated FA ≥3 months prior to pregnancy (38.1%) had a 23% [hazard ratio (HR)=0.77 (95% CI: 0.76, 0.78)] lower risk of PTD than women who did not use preconception FA. Participants with PM concentrations in the highest quartile had a higher risk of PTD [HR=1.29 (95% CI: 1.26, 1.32) for PM1, 1.52 (95% CI: 1.46, 1.58) for PM2.5, and 1.22 (95% CI: 1.17, 1.27) for PM10] than those with exposures in the lowest PM quartiles. Estimated associations with a 10-μg/m3 increase in PM1 and PM2.5 were significantly lower among women who initiated FA ≥3 months prior to pregnancy [HR=1.09 (95% CI: 1.08, 1.10) for both exposures] than among women who did not use preconception FA [HR=1.12 (95% CI: 1.11, 1.13) for both exposures; pinteraction<0.001]. The corresponding association was also significantly lower for a 10-μg/m3 increase in PM10 [HR=1.03 (95% CI: 1.02, 1.03) for FA ≥3 months before pregnancy vs. 1.04 (95% CI: 1.03, 1.04) for no preconception FA; pinteraction<0.001].Conclusion: Our findings require confirmation in other populations, but they suggest that initiating FA supplementation ≥3 months prior to pregnancy may lessen the risk of PTD associated with PM exposure during pregnancy among primiparas of Han ethnicity. https://doi.org/10.1289/EHP6386     

Environmental Spread of Extended Spectrum Beta-Lactamase (ESBL) Producing Escherichia coli and ESBL Genes among Children and Domestic Animals in Ecuador

Background: There is a significant gap in our understanding of the sources of multidrug-resistant bacteria and resistance genes in community settings where human–animal interfaces exist.Objectives: This study characterized the relationship of third-generation cephalosporin-resistant Escherichia coli (3GCR-EC) isolated from animal feces in the environment and child feces based on phenotypic antimicrobial resistance (AMR) and whole genome sequencing (WGS).Methods: We examined 3GCR-EC isolated from environmental fecal samples of domestic animals and child fecal samples in Ecuador. We analyzed phenotypic and genotypic AMR, as well as clonal relationships (CRs) based on pairwise single-nucleotide polymorphisms (SNPs) analysis of 3GCR-EC core genomes. CRs were defined as isolates with fewer than 100 different SNPs.Results: A total of 264 3GCR-EC isolates from children (n=21), dogs (n=20), and chickens (n=18) living in the same region of Quito, Ecuador, were identified. We detected 16 CRs total, which were found between 7 children and 5 domestic animals (5 CRs) and between 19 domestic animals (11 CRs). We observed that several clonally related 3GCR-EC isolates had acquired different plasmids and AMR genes. Most CRs were observed in different homes (n=14) at relatively large distances. Isolates from children and domestic animals shared the same blaCTX-M allelic variants, and the most prevalent were blaCTX-M-55 and blaCTX-M-65, which were found in isolates from children, dogs, and chickens.Discussion: This study provides evidence of highly dynamic horizontal transfer of AMR genes and mobile genetic elements (MGEs) in the E. coli community and shows that some 3GCR-EC and (extended-spectrum β-lactamase) ESBL genes may have moved relatively large distances among domestic animals and children in semirural communities near Quito, Ecuador. Child–animal contact and the presence of domestic animal feces in the environment potentially serve as important sources of drug-resistant bacteria and ESBL genes. https://doi.org/10.1289/EHP7729     

Dynamic lung function changes following long-term work in polluted environments

Ten young males (mean age 23.1 years) and nine middle-aged males (mean age 47.8 years) forming two groups (smokers and nonsmokers) performed a simple spirometric evaluation test prior to and following 4 hours exposure to four ambient conditions at two temperatures: 25°C dry bulb (DB), 30% rh and 35°C DB, 30% rh). The ambient conditions were filtered air, 50 ppm carbon monoxide in filtered air, 0.24 ppm peroxyacetylnitrate (PAN) in filtered air, and a combination of all three above conditions. During the 4-hour exposure, the subjects performed 3.5 hours of submaximal work (35% VO₂max) resulting in a ventilation of 20–30 liters/min BTPS. The FVC of the younger subjects was reduced (4–7%) following exposure to conditions containing peroxyacetylnitrate (P < 0.05). The older subjects had no significant change in pulmonary function due to pollutants, suggesting an age-related susceptibility to the oxidant pollutants, such as PAN. Thermal stress reduced the FVC of younger subjects 5.5% (P < 0.01). There were no interactions between pollutants, temperature, or smoking habits. Exercise alone was effective in changing $\text{FEV}{}_{1.0}\text{FVC}$, % of all subjects of both age groups. It was suggested that oxidant-type pollutants act on the dependent regions of the lung, while exercise appeared to stimulate the lung during forceful expiration.     

Ozone Exposure,Outdoor Physical Activity,and Incident Type 2 Diabetes in the SALSA Cohort of Older Mexican Americans

Background: Type 2 diabetes is a leading contributor to the global burden of morbidity and mortality. Ozone (O3) exposure has previously been linked to diabetes.Objective: We studied the impact of O3 exposure on incident diabetes risk in elderly Mexican Americans and investigated whether outdoor physical activity modifies the association.Methods: We selected 1,090 Mexican American participants from the Sacramento Area Latino Study on Aging conducted from 1998 to 2007. Ambient O3 exposure levels were modeled with a land-use regression built with saturation monitoring data collected at 49 sites across the Sacramento metropolitan area. Using Cox proportional hazard models, we estimated the risk of developing incident diabetes based on average O3 exposure modeled for 5-y prior to incident diabetes diagnosis or last follow-up. Further, we estimated outdoor leisure-time physical activity at baseline and investigated whether higher vs. lower levels modified the association between O3 exposure and diabetes.Results: In total, 186 incident diabetes cases were identified during 10-y follow-up. Higher levels of physical activity were negatively associated with incident diabetes [hazard ratio (HR)=0.64 (95% CI: 0.43, 0.95)]. The estimated HRs for incident diabetes was 1.13 (95% CI: 1.00, 1.28) per 10-ppb increment of 5-y average O3 exposure; also, this association was stronger among those physically active outdoors [HR=1.52 (95% CI: 1.21, 1.90)], and close to null for those reporting lower levels of outdoor activity [HR=1.04 (95% CI: 0.90, 1.20), pinteraction=0.01].Conclusions: Our findings suggest that ambient O3 exposure contributes to the development of type 2 diabetes, particularly among those with higher levels of leisure-time outdoor physical activity. Policies and strategies are needed to reduce O3 exposure to guarantee that the health benefits of physical activity are not diminished by higher levels of O3 pollution in susceptible populations such as older Hispanics. https://doi.org/10.1289/EHP8620     

Human Colonization with Extended-Spectrum Beta-Lactamase-Producing E. coli in Relation to Animal and Environmental Exposures in Bangladesh: An Observational One Health Study

Background: Human exposure to intensively farmed livestock is a potential risk for transmission of antibiotic-resistant bacteria (ARB) but few studies have assessed the relative role of animal vs. environmental sources of ARB in low-resource community settings.Objectives: We conducted an observational study to compare ARB colonization and antibiotic-resistant gene prevalence and abundance in humans with high or low exposure to poultry in rural households, commercial poultry farms, and urban markets in Bangladesh.Methods: Extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant E. coli were quantified in feces from adults with high or low poultry exposure (n=100, respectively), poultry (n=200), drinking water (n=120), and wastewater (n=120) from 40 rural households, 40 poultry farms, and 40 urban markets.Results: ESBL-producing E. coli (ESBL-EC) prevalence was 67.5% (95% CI: 61.0, 74.0) in samples from adults, 68.0% (95% CI: 61.5, 74.5) in samples from poultry, and 92.5% (95% CI: 87.7, 97.3) in wastewater samples. Carbapenem-resistant E. coli prevalence was high in market wastewaters [30% (95% CI: 15.0, 45.0)] but low in humans (1%) and poultry (1%). Human, poultry, and wastewater isolates shared common resistance genes: blaCTX-M-1, qnr, and blaTEM. Human colonization was not significantly associated with exposure to poultry or setting (rural, farm, or market). Ninety-five percent of commercial poultry farms routinely administered antibiotics. Susceptibility tests were significantly different in household vs. farm and market poultry isolates for four of seven antibiotic classes. In human isolates, there were no differences except aminoglycoside resistance (16.4% high vs. 4.4% low exposure, p=0.02). Urban market wastewaters and poultry samples had significantly higher concentrations of ESBL-EC (p<0.001) and blaCTX-M-1 (p<0.001) compared with samples from farms and rural households.Discussion: ESBL-EC colonization was high in humans but not significantly associated with exposure to poultry. Bidirectional transmission of antibiotic resistance is likely between humans, poultry, and the environment in these community settings, underlining the importance of One Health mitigation strategies. https://doi.org/10.1289/EHP7670     

Long-Term Exposure to Transportation Noise and Risk of Incident Stroke: A Pooled Study of Nine Scandinavian Cohorts

Background: Transportation noise is increasingly acknowledged as a cardiovascular risk factor, but the evidence base for an association with stroke is sparse.Objective: We aimed to investigate the association between transportation noise and stroke incidence in a large Scandinavian population.Methods: We harmonized and pooled data from nine Scandinavian cohorts (seven Swedish, two Danish), totaling 135,951 participants. We identified residential address history and estimated road, railway, and aircraft noise for all addresses. Information on stroke incidence was acquired through linkage to national patient and mortality registries. We analyzed data using Cox proportional hazards models, including socioeconomic and lifestyle confounders, and air pollution.Results: During follow-up (median=19.5y), 11,056 stroke cases were identified. Road traffic noise (Lden) was associated with risk of stroke, with a hazard ratio (HR) of 1.06 [95% confidence interval (CI): 1.03, 1.08] per 10-dB higher 5-y mean time-weighted exposure in analyses adjusted for individual- and area-level socioeconomic covariates. The association was approximately linear and persisted after adjustment for air pollution [particulate matter (PM) with an aerodynamic diameter of ≤2.5μm (PM2.5) and NO2]. Stroke was associated with moderate levels of 5-y aircraft noise exposure (40–50 vs. ≤40 dB) (HR=1.12; 95% CI: 0.99, 1.27), but not with higher exposure (≥50 dB, HR=0.94; 95% CI: 0.79, 1.11). Railway noise was not associated with stroke.Discussion: In this pooled study, road traffic noise was associated with a higher risk of stroke. This finding supports road traffic noise as an important cardiovascular risk factor that should be included when estimating the burden of disease due to traffic noise. https://doi.org/10.1289/EHP8949     

Air Pollution and Polyclonal Elevation of Serum Free Light Chains: An Assessment of Adaptive Immune Responses in the Prospective Heinz Nixdorf Recall Study

Background: Residential exposure to air pollution (AP) has been shown to activate the immune system (IS). Although innate immune responses to AP have been studied extensively, investigations on the adaptive IS are scarce.Objectives: The aim of this study was to investigate the association between short- to long-term AP exposure and polyclonal free light chains (FLC) produced by plasma cells.Methods: We used repeated data from three examinations (t0: 2000–2003; t1: 2006–2008; and t2: 2011–2015) of the population-based German Heinz Nixdorf Recall cohort of initially 4,814 participants (45–75 y old). Residential exposure to total and source-specific particulate matter (PM) with an aerodynamic diameter of 10 or 2.5μm (PM10 and PM2.5 respectively), nitrogen dioxide (NO2), and particle number concentrations (accumulation mode; PNAM) was estimated using a chemistry transport model with different time windows (1- to 365-d mean ± standard deviation) before blood draw. We applied linear mixed models with a random participant intercept to estimate associations between total, traffic- and industry-related AP exposures and log-transformed FLC, controlling for examination time, sociodemographic and lifestyle variables, estimated glomerular filtration rate and season.Results: Analyzing 9,933 observations from 4,455 participants, we observed generally positive associations between AP exposures and FLC. We observed strongest associations with middle-term exposures, e.g., 3.0% increase in FLC (95% confidence interval: 1.8%, 4.3%) per interquartile range increase in 91-d mean of NO2 (14.1μg/m³). Across the different pollutants, NO2 showed strongest associations with FLC, followed by PM10 and PNAM. Effect estimates for traffic-related exposures were mostly higher compared with total exposures. Although NO2 and PNAM estimates remained stable upon adjustment for PM, PM estimates decreased considerably upon adjustment for NO2 and PNAM.Discussion: Our results suggest that middle-term AP exposures in particular might be positively associated with activation of the adaptive IS. Traffic-related PM, PNAM, and NO2 showed strongest associations. https://doi.org/10.1289/EHP7164