Landfill fire and airborne aerosols in a large city: lessons learned and future needs

Landfill fires are relatively frequent incidents that can result in severe environmental impacts. On the morning of January 15, 2016, a fire occurred at the Santa Marta landfill (Lf) in the metropolitan area of Santiago (SMA), Chile. The fire triggered public alarm. In the present work, the impact of the landfill fire on the air quality of the SMA and the possible impacts on human health are analyzed. According to the information collected, the fire began after a collapse in the landfill on January 15, 2016. The fire could not be controlled by the Lf operating company, and authorities acted late in responding. The results revealed that at the focal point of the fire, particulate matter with an aerodynamic diameter smaller than 2.5 μm (PM_2.5) reached concentration levels on the order of 1000 μg m^?3. Three days after the start of the fire, hourly PM_2.5 concentration levels above 200 μg m^?3 were recorded, at a distance approximately 20 km northeast of where the fire occurred. The PM_2.5 concentration levels recommended for the protection of the health of vulnerable persons were subsequently exceeded. These results suggest that a preventive measure should have been the evacuation of the most pollution-sensitive population. An inappropriate management of the emergency was demonstrated. Legislation should be improved by stipulating which sanitary Lfs should be equipped with firefighting equipment. Territorial planning should be improved by considering geographic and meteorological aspects.     

Particulate nitrosamines in the atmosphere at Seoul and their major sources

Five nitrosamines (nitroso-methyl-ethylamine (NMEA), nitroso-pyrrolidine (NPYR), nitrosodi-ethylamine (NDEA), nitroso-piperidine (NPIP), and nitrosodi-butylamine (NDBA)) in the atmospheric particulate matter with an aerodynamic diameter of less than or equal to a nominal 10 μm (PM₁₀) at Seoul were identified and quantified by using a gas chromatography/mass spectrometry (GC/MS) in chemical ionization (CI) mode. The average ambient concentrations of the sum of the five nitrosamines showed a distinctive seasonal pattern, higher in winter (2.79?±?1.41 ng/m³) than in summer (0.92?±?0.29 ng/m³). Diurnal pattern showed slightly higher in night time (1.67?±?1.47 ng/m³) than day time (1.57?±?1.04 ng/m³) but it was not statistically significant. Possible contributors of nitrosamines were discussed based on various statistical analyses. Since BaP/BeP ratio and nitrosamines’ concentrations showed negative correlation, indicating aged aerosols containing more nitrosamines, it was suggested that nitrosamines might be produced by the atmospheric reactions. However, the correlations of nitrosamines with PAHs, CO, and SO₂ were also good which were emitted from the primary emission sources, suggesting the particulate nitrosamines observed at Seoul could be also emitted from the primary emission sources. Primary emission sources were also identified by using the principal component analysis (PCA). It was concluded that NDBA could be mainly emitted from plastic and rubber combustions, release of landfill and tobacco smoke, and NPYR and NDEA might be emitted from the vehicular emission and cooking. The other nitrosamines, NMEA and NPIP, which were not included in both factors and showed relatively higher negative correlation with BaP/BeP ratios than other nitrosamines, could be produced from the atmospheric reactions.     

A study of Winston–Lutz test on two different electronic portal imaging devices and with low energy imaging

Stereotactic radiosurgery requires sub-millimetre accuracy in patient positioning and target localization. Therefore, verification of the linear accelerator (linac) isocentre and the laser alignment to the isocentre is performed in some clinics prior to the treatment using the Winston–Lutz (W–L) test with films and more recently with images obtained using the electronic portal imaging devices (EPID). The W–L test is performed by acquiring EPID images of a radio-opaque ball of 6 mm diameter (the W–L phantom) placed at the isocentre of the linac at various gantry and table angles, with a predefined small square or circular radiation beam. In this study, the W–L test was performed on two linacs having EPIDs of different size and resolution, viz, a TrueBeam? linac with aS1000 EPID of size 40 × 30 cm² with 1024 × 768 pixel resolution and an EDGE? linac having an EPID of size 43 × 43 cm² with pixel resolution of 1280 × 1280. In order to determine the displacement of the radio-opaque ball centre from the radiation beam centre of the W–L test, an in-house MATLAB? image processing code was developed using morphological operations. The displacement in radiation beam centre at each gantry and couch position was obtained by determining the distance between the radiation field centre and the radio-opaque ball centre for every image. Since the MATLAB code was based on image processing that was dependent on the image contrast and resolution, the W–L test was also compared for images obtained with different beam energies. The W–L tests were performed for 6 and 8 MV beams on the TrueBeam? linac and for 2.5 and 6 MV beams on the EDGE? linac with a higher resolution EPID. It was observed that the images obtained with the EPID of higher resolution resulted in same accuracy in the determination of the displacement between the centres of the radio-opaque ball and the radiation beam, and significant difference was not observed with images acquired with different energies. It is concluded that the software based on morphological operations provided an accurate estimation of the displacement of the ball centre from the radiation beam center.     

Satellite monitoring of forest fires and associated smoke plumes occurring in Korea

Operational research was carried out on satellite detection of forest fires and associated smoke plumes occurring in the Korean Peninsula. Forest fire data and satellite images obtained from 2004 to 2007 were examined. It was observed that at least three forest-fire episodes were caused by atmospheric lightning, while all other cases were recorded as anthropogenic causes, according to data gathered from the Korean meteorological and forestry services. For two episodes, there were 60~120 forest fires in North and South Korea, observations based on hotspots analysis. Smoke plumes transported over 1,200 km were observed. There was discussion of the role played by the emission of heated air and greenhouse gases in general warming and climate change in regional and global atmospheres, e.g., Arctic ice melting. With global warming, ice over the Arctic Ocean is melting significantly in summer (Chung and Le, Int J Remote Sens 25(2):front cover and 291–296, 2004). The suppression of forest fires caused by human activities is suggested to improve the atmospheric environment and to prevent climate change in the near future.     

Parents’ Depressive Symptoms and Gun,Fire, and Motor Vehicle Safety Practices

Objective This study examined associations between mothers’ and fathers’ depressive symptoms and their parenting practices relating to gun, fire, and motor vehicle safety. Methods Using data from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), a nationally representative sample of children birth to age five, linear probability models were used to examine associations between measures of parents’ depressive symptoms and their use of firearms, smoke detectors, and motor vehicle restraints. Parents reported use of smoke detectors, motor vehicle restraints, and firearm ownership and storage. Results Results suggest mothers with moderate or severe depressive symptoms were 2 % points less likely to report that their child always sat in the back seat of the car, and 3 % points less likely to have at least one working smoke detector in the home. Fathers’ depressive symptoms were associated with a lower likelihood of both owning a gun and of it being stored locked. Fathers’ depressive symptoms amplified associations between mothers’ depressive symptoms and owning a gun, such that having both parents exhibit depressive symptoms was associated with an increased likelihood of gun ownership of between 2 and 6 % points. Conclusions Interventions that identify and treat parental depression early may be effective in promoting appropriate safety behaviors among families with young children.     

Source term assessment using inverse modeling and environmental radiation measurements for nuclear emergency response

A simple model ‘Assessment of Source Term for Emergency Response (ASTER)’ for estimation of time-dependent atmospheric source term based on real-time environmental gamma dose rate measurements is developed for application in Online Nuclear Emergency Response System (ONERS). The model inverts the measured dose rates to the airborne radioactive release rate using the dilution factors predicted by a random-walk particle atmospheric dispersion model called System for Prediction of Environmental Emergency Dose Information (SPEEDI) taking into account the real-time meteorological observations and location coordinates of the gamma radiation detectors. A point-kernel method for estimating the cloud-gamma dose rates at receptor locations is implemented in SPEEDI for this purpose. ASTER is validated against Ar-41 routine release data from a pressurized heavy-water reactor (PHWR) at Kalpakkam for over 100 days covering different seasons during 2014–2015. Comparison of ASTER-simulated overhead plume gamma dose rates with the measured dose rates at detector points gives a correlation of R = 0.59, bias of 89 nGy/h, and RMSE of 104.09 nGy/h indicating a slight overestimation of gamma dose rates at monitor points. Comparison of ASTER-predicted source term with Ar-41 release rates indicated that about 90% of the calculations fall within a factor of 5 of the actual source term. A correlation of 0.584, bias of 0.152 TBq/day, and RMSE of 0.192 TBq/day are found between the computed and actual daily source term values indicating reasonable agreement. The slight underestimation in the computed source term is due to the overestimation of the dose rate by the dispersion model, location of few monitors near buildings and tree canopies, uneven distribution of detectors in various wind direction sectors, and the use of daily source term values for comparison.     

The effect of meteorological conditions on aerosol size distribution in Istanbul

Ambient aerosols were sampled by a high-volume cascade impactor in Istanbul, through May 2012 and November 2014. Seventy-eight size-segregated samples were gathered within the period at six different stages. The particles exhibited tri-modal distribution. The peak at <0.49 μm was the most dominant among the others. The average mass median diameter was 1.3 μm. The average total suspended particulate concentration was 75 μg m^?3, and PM₁₀, PM₄, PM_2.5, and PM₁ concentrations, derived from log-probability plots, were 62.5, 52.9, 46.9, and 34.2 μg m^?3, respectively. Particle concentrations related to meteorological conditions through Pearson’s correlation coefficient. The Pearson’s correlation coefficient was poor in describing the association between coarse particles and meteorological conditions due to the increased urban effect, short-range transportation of marine aerosols, and long-range transportation. Particles >7.2 and 7.2–3 μm had a strong relation, indicating same sources. Increased relative humidity enriched 0.95–1.5-μm particle fraction in winter. Particles between 0.49 and 3 μm were inversely related to ambient temperature. Dilution effect of the wind was significant for PM_1.5. Wind acted as a source for larger particles by carrying them from other source regions. Multiple linear regression was applied to particulate matter fractions in order to model the concentrations of each fraction related to meteorological data. In the model, the particle fractions of 1.5–0.95 and 0.95–0.49 μm exhibited the highest prediction performance.     

Pilot Study of a Novel Partnership for Installing Smoke Alarms

Objectives To demonstrate the feasibility of partnering fire department personnel and home visiting nurses to increase the number of low-income homes protected by smoke alarms. Methods During a regularly scheduled home visit, nurses at the Nurse-Family Partnership of Maricopa County (NFP) informed their clients about an opportunity to have smoke alarms installed in their homes for free. For interested families, nurses sent a referral to the Phoenix Fire Department (PFD), scheduled an appointment, and accompanied the PFD volunteers during the installation. During the appointment, PFD personnel installed alarms and provided safety education. Clients completed a follow-up survey 1–3 months after the installation visit. In-depth interviews were completed with key informants from NFP and PFD to solicit feedback on the program. Results Fifty-two smoke alarm installation visits were completed. Before the fire department arrived, 55% of homes had no working smoke alarm. Almost all (94%) homes received at least one new smoke alarm, and every home had at least one working smoke alarm at the end of the fire department visit. At follow-up, all homes maintained at least one working smoke alarm. Members from both organizations were enthusiastic about, and supportive of the project. NFP nurses appreciated the skill and knowledge of the firefighters; PFD representatives noted that the nurses’ relationships with clients made it easier for them to gain access to families who are often described as “hard-to-reach”. Conclusions Partnering home visiting nurses and fire departments can be successful to increase the number of vulnerable homes with smoke alarms.     

Potential local and regional impacts of particulate matter emitted from one of the world’s largest open-pit coal mines

This study was designed to evaluate the atmospheric total suspended particle (TSP) and particulate matter (PM₁₀) concentrations and temporal variability in one of the world’s largest open-pit coal mines (El Cerrejon) located in northeast Colombia, during 2012–2016. The results showed overall average TSP and PM₁₀ concentrations of 86 μg m^?3 (CI_95% 84–88 μg m^?3) and 34 μg m^?3 (CI_95% 33–35 μg m^?3), respectively, with the highest concentrations between March and August each year. A time trend analysis of the results revealed that PM₁₀ concentrations in particular have significantly increased between 6.2 and 7.7% per year (CI_95% 1.2–12.8% year^?1) in several of the monitoring stations. Meteorological parameters were also evaluated. It was observed that NE winds with speeds above 2 m s^?1 were significantly correlated with an increase in the concentration of PM₁₀ for selected downwind sites, which suggested that coal mining operations are an important source of atmospheric PM in the area. Regional long-range atmospheric transport scenarios showed potential effects on neighboring municipalities and countries within 72-h transportation events. These highlighted the need to develop new strategies to control the emissions of PM from the local mining industry to comply with local and international guidelines and regulations, particularly when industrial expansion is planned for the near future and relatively large population centers are in the area, of which a high proportion belong to indigenous populations.