SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Cruise ship pollution

204

Air pollution is a suspected developmental neurotoxicant. Many schools are located in close proximity to busy roads, and traffic air pollution peaks when children are at school. We aimed to assess whether exposure of children in primary school to traffic-related air pollutants is associated with impaired cognitive development.

Concepts: Primary school, Primary education, School, Cruise ship pollution

137

China has been suffering from serious air pollution for years in response to the rapid industrialization and urbanization. Notably Beijing is one of the most polluted capitals in the world. Hence, the focus of the study area is on Beijing. In the first stage, we analyze spatial and temporal characteristics of air pollution of the 6 cities while in the second stage the Granger causality test is applied to investigate whether air pollution of a city is affected by its neighbors, and vice versa. The findings are the following. Overall, AQI values are high in winter and early spring while low in summer and autumn. Among the 6 cities, Baoding is the major contributor to air pollution in this entire area. Besides, Granger causality test results show that there is a unidirectional relationship running from Baoding to Beijing and a bidirectional relationship between Beijing and Tianjin. In other words, apart from local air pollutants, for example, exhaust gas, air quality of Beijing is affected by air pollution of Tianjin, and vice versa. However, regarding the relationship between Beijing and Baoding, air quality of Beijing is just affected by air pollution of Baoding, since Baoding is much polluted than Beijing.

Concepts: Causality, People's Republic of China, Pollution, Smog, Air pollution, Cruise ship pollution, Air Quality Index, Granger causality

78

Policymakers around the world are turning to license-plate based driving restrictions in an effort to address urban air pollution. The format differs across cities, but most programs restrict driving once or twice a week during weekdays. This paper focuses on Mexico City, home to one of the oldest and best-known driving restriction policies. For almost two decades Mexico City’s driving restrictions applied during weekdays only. This changed recently, however, when the program was expanded to include Saturdays. This paper uses hourly data from pollution monitoring stations to measure the effect of the Saturday expansion on air quality. Overall, there is little evidence that the program expansion improved air quality. Across eight major pollutants, the program expansion had virtually no discernible effect on pollution levels. These disappointing results stand in sharp contrast to estimates made before the expansion which predicted a 15%+ decrease in vehicle emissions on Saturdays. To understand why the program has been less effective than expected, the paper then turns to evidence from subway, bus, and light rail ridership, finding no evidence that the expansion was successful in getting drivers to switch to lower-emitting forms of transportation.

Concepts: Pollution, Smog, National Ambient Air Quality Standards, Air pollution, Los Angeles, Cruise ship pollution, Chicago, Air Quality Index

61

Exposure to ambient air pollutants has been associated with increased lung cancer incidence and mortality, but due to the high case fatality rate, little is known about the impacts of air pollution exposures on survival after diagnosis. This study aimed to determine whether ambient air pollutant exposures are associated with the survival of patients with lung cancer.

Concepts: Epidemiology, Lung cancer, Pollution, Environmentalism, National Ambient Air Quality Standards, Air pollution, Acid rain, Cruise ship pollution

49

Objective: Air pollution contains many toxicants known to affect neurological function and to have effects on the fetus in utero. Recent studies have reported associations between perinatal exposure to air pollutants and autism spectrum disorder (ASD) in children. We tested the hypothesis that perinatal exposure to air pollutants is associated with ASD, focusing on pollutants associated with ASD in prior studies.Methods: We estimated associations between U.S. Environmental Protection Agency-modeled levels of hazardous air pollutants at the time and place of birth and ASD in the children of participants in the Nurses' Health Study II (325 cases, 22,101 controls). Our analyses focused on pollutants associated with ASD in prior research. We accounted for possible confounding and ascertainment bias by adjusting for family-level socioeconomic status (maternal grandparents' education) and census tract-level socioeconomic measures (e.g., tract median income and percent college educated), as well as maternal age at birth and year of birth. We also examined possible differences in the relationship between ASD and pollutant exposures by child’s sex.Results: Perinatal exposures to the highest versus lowest quintile of diesel, lead, manganese, mercury, methylene chloride, and an overall measure of metals were significantly associated with ASD, with odds ratios ranging from 1.5 (for overall metals measure) to 2.0 (for diesel and mercury). In addition, linear trends were positive and statistically significant for these exposures (p < .05 for each). For most pollutants, associations were stronger for boys (279 cases) than for girls (46 cases) and significantly different according to sex.Conclusions: Perinatal exposure to air pollutants may increase risk for ASD. Additionally, future studies should consider sex-specific biological pathways connecting perinatal exposure to pollutants with ASD.

Concepts: Pollution, Autism spectrum, United States Environmental Protection Agency, Environmentalism, Air pollution, Cruise ship pollution, Hazardous air pollutants, Air dispersion modeling

45

To study the correlation between the levels of environmental pollutants and the number of paediatric consultations related to respiratory disease in Primary Health Care.

Concepts: Health care, Medicine, Biodiversity, Environment, Pollution, Environmentalism, Acid rain, Cruise ship pollution

26

Air pollution is a major health challenge worldwide and has previously been strongly associated with adverse reproductive health. This study aimed to examine the association between spontaneous abortion and seasonal variation of air pollutants in Ulaanbaatar, Mongolia.

Concepts: People's Republic of China, Pollution, Environmentalism, National Ambient Air Quality Standards, Air pollution, Acid rain, Cruise ship pollution, Biofilter

26

The mechanisms by which air pollution has multiple systemic effects in humans are not fully elucidated, but appear to include inflammation and thrombosis. This study examines whether concentrations of ozone and components of fine particle mass are associated with changes in methylation on tissue factor (F3), interferon gamma (IFN-γ), interleukin 6 (IL-6), toll-like receptor 2 (TLR-2), and intercellular adhesion molecule 1 (ICAM-1). We investigated associations between air pollution exposure and gene-specific methylation in 777 elderly men participating in the Normative Aging Study (1999-2009). We repeatedly measured methylation at multiple CpG sites within each gene’s promoter region and calculated the mean of the position-specific measurements. We examined intermediate-term associations between primary and secondary air pollutants and mean methylation and methylation at each position with distributed-lag models. Increase in air pollutants concentrations was significantly associated with F3, ICAM-1, and TLR-2 hypomethylation, and IFN-γ and IL-6 hypermethylation. An interquartile range increase in black carbon concentration averaged over the four weeks prior to assessment was associated with a 12% reduction in F3 methylation (95% CI: -17% to -6%). For some genes, the change in methylation was observed only at specific locations within the promoter region. DNA methylation may reflect biological impact of air pollution. We found some significant mediated effects of black carbon on fibrinogen through a decrease in F3 methylation, and of sulfate and ozone on ICAM-1 protein through a decrease in ICAM-1 methylation.

Concepts: Immune system, DNA, Gene, Toll-like receptor, Particulate, Intercellular adhesion molecule, Air pollution, Cruise ship pollution

24

24

Multivariate statistical techniques were employed on twelve leaf traits in four selected common tree species (Mangifera indica L., Polyalthia longifolia Sonn., Ficus benghalensis L. and Psidium guajava L.) to evaluate their responses with respect to major air pollutants in an urban area. Discriminant analysis (DA) identified chlorophyll/carotenoid ratio, leaf dry matter content, carotenoids, net water content and ascorbic acid as the major discriminating leaf traits, which varied maximally with respect to the pollution status. Pollution response score (PRS), calculated on the basis of discriminate functional coefficient values, increased with an increase in air pollution variables for all the tested species, with the highest increase in P. longifolia and the lowest in F. benghalensis. The study highlights the usefulness of DA for evaluation of plant specific traits and PRS for selection of tolerant species.

Concepts: Water, Pollution, National Ambient Air Quality Standards, Air pollution, Acid rain, Cruise ship pollution, Psidium guajava, Ficus benghalensis