Traffic-related air pollution and respiratory symptoms among asthmatic children,resident in Mexico City: the EVA cohort study

Background

Taffic-related air pollution has been related to adverse respiratory outcomes; however, there is still uncertainty concerning the type of vehicle emission causing most deleterious effects.

Methods

A panel study was conducted among 147 asthmatic and 50 healthy children, who were followed up for an average of 22 weeks. Incidence density of coughing, wheezing and breathing difficulty was assessed by referring to daily records of symptoms and child''s medication. The association between exposure to pollutants and occurrence of symptoms was evaluated using mixed-effect models with binary response and poisson regression.

Results

Wheezing was found to relate significantly to air pollutants: an increase of 17.4 μg/m³ (IQR) of PM_2.5 (24-h average) was associated with an 8.8% increase (95% CI: 2.4% to 15.5%); an increase of 34 ppb (IQR) of NO₂ (1-h maximum) was associated with an 9.1% increase (95% CI: 2.3% to16.4%) and an increase of 48 ppb (IQR) in O₃ levels (1 hr maximum) to an increase of 10% (95% CI: 3.2% to 17.3%). Diesel-fueled motor vehicles were significantly associated with wheezing and bronchodilator use (IRR = 1.29; 95% CI: 1.03 to 1.62, and IRR = 1.32; 95% CI: 0.99 to 1.77, respectively, for an increase of 130 vehicles hourly, above the 24-hour average).

Conclusion

Respiratory symptoms in asthmatic children were significantly associated with exposure to traffic exhaust, especially from natural gas and diesel-fueled vehicles.     

Dietary intake,lung function and airway inflammation in Mexico City school children exposed to air pollutants

Introduction

Air pollutant exposure has been associated with an increase in inflammatory markers and a decline in lung function in asthmatic children. Several studies suggest that dietary intake of fruits and vegetables might modify the adverse effect of air pollutants.

Methods

A total of 158 asthmatic children recruited at the Children''s Hospital of Mexico and 50 non-asthmatic children were followed for 22 weeks. Pulmonary function was measured and nasal lavage collected and analyzed every 2 weeks. Dietary intake was evaluated using a 108-item food frequency questionnaire and a fruit and vegetable index (FVI) and a Mediterranean diet index (MDI) were constructed. The impact of these indices on lung function and interleukin-8 (IL-8) and their interaction with air pollutants were determined using mixed regression models with random intercept and random slope.

Results

FVI was inversely related to IL-8 levels in nasal lavage (p < 0.02) with a significant inverse trend (test for trend p < 0.001), MDI was positively related to lung function (p < 0.05), and children in the highest category of MDI had a higher FEV₁ (test for trend p < 0.12) and FVC (test for trend p < 0.06) than children in the lowest category. A significant interaction was observed between FVI and ozone for FEV₁ and FVC as was with MDI and ozone for FVC. No effect of diet was observed among healthy children.

Conclusion

Our results suggest that fruit and vegetable intake and close adherence to the Mediterranean diet have a beneficial effect on inflammatory response and lung function in asthmatic children living in Mexico City.     

兰州市西固区大气污染对呼吸系统的健康效应

大气污染极易诱发各类呼吸系统疾病,对人体健康造成严重损害。运用Poisson回归的时间序列广义相加模型(GAM)和人群分层的分析方法,探究了2014—2018年兰州市西固区大气污染对呼吸系统的健康效应。结果表明：(1)PM_2.5、PM₁₀、SO₂、NO₂、O₃8h和CO对呼吸系统疾病的发生存在滞后效应,其浓度每升高10μg/m~3(CO升高1 mg/m~3),在最佳滞后天数,疾病住院量分别增加1.06%、1.04%、1.10%、1.07%、0.97%和3.83%,气态污染物(SO₂和NO₂)暴露是诱发呼吸系统疾病的重要风险因素;(2)PM_2.5、PM₁₀、SO₂和NO₂对肺炎的影响最大,且对女性健康的危害稍高于男性,O₃8h对慢性阻塞性肺病的影响最大,且对男性患病的影响稍高于女性;(3)0—14岁儿童是呼吸系统疾病的易感人群,...     

Effect of ambient air pollution on the incidence of appendicitis

Background

The pathogenesis of appendicitis is unclear. We evaluated whether exposure to air pollution was associated with an increased incidence of appendicitis.

Methods

We identified 5191 adults who had been admitted to hospital with appendicitis between Apr. 1, 1999, and Dec. 31, 2006. The air pollutants studied were ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, and suspended particulate matter of less than 10 μ and less than 2.5 μ in diameter. We estimated the odds of appendicitis relative to short-term increases in concentrations of selected pollutants, alone and in combination, after controlling for temperature and relative humidity as well as the effects of age, sex and season.

Results

An increase in the interquartile range of the 5-day average of ozone was associated with appendicitis (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.03–1.25). In summer (July–August), the effects were most pronounced for ozone (OR 1.32, 95% CI 1.10–1.57), sulfur dioxide (OR 1.30, 95% CI 1.03–1.63), nitrogen dioxide (OR 1.76, 95% CI 1.20–2.58), carbon monoxide (OR 1.35, 95% CI 1.01–1.80) and particulate matter less than 10 μ in diameter (OR 1.20, 95% CI 1.05–1.38). We observed a significant effect of the air pollutants in the summer months among men but not among women (e.g., OR for increase in the 5-day average of nitrogen dioxide 2.05, 95% CI 1.21–3.47, among men and 1.48, 95% CI 0.85–2.59, among women). The double-pollutant model of exposure to ozone and nitrogen dioxide in the summer months was associated with attenuation of the effects of ozone (OR 1.22, 95% CI 1.01–1.48) and nitrogen dioxide (OR 1.48, 95% CI 0.97–2.24).

Interpretation

Our findings suggest that some cases of appendicitis may be triggered by short-term exposure to air pollution. If these findings are confirmed, measures to improve air quality may help to decrease rates of appendicitis.Appendicitis was introduced into the medical vernacular in 1886.¹ Since then, the prevailing theory of its pathogenesis implicated an obstruction of the appendiceal orifice by a fecalith or lymphoid hyperplasia.² However, this notion does not completely account for variations in incidence observed by age,^3,4 sex,^3,4 ethnic background,^3,4 family history,⁵ temporal–spatial clustering⁶ and seasonality,^3,4 nor does it completely explain the trends in incidence of appendicitis in developed and developing nations.^3,7,8The incidence of appendicitis increased dramatically in industrialized nations in the 19th century and in the early part of the 20th century.¹ Without explanation, it decreased in the middle and latter part of the 20th century.³ The decrease coincided with legislation to improve air quality. For example, after the United States Clean Air Act was passed in 1970,⁹ the incidence of appendicitis decreased by 14.6% from 1970 to 1984.³ Likewise, a 36% drop in incidence was reported in the United Kingdom between 1975 and 1994¹⁰ after legislation was passed in 1956 and 1968 to improve air quality and in the 1970s to control industrial sources of air pollution. Furthermore, appendicitis is less common in developing nations; however, as these countries become more industrialized, the incidence of appendicitis has been increasing.⁷Air pollution is known to be a risk factor for multiple conditions, to exacerbate disease states and to increase all-cause mortality.¹¹ It has a direct effect on pulmonary diseases such as asthma¹¹ and on nonpulmonary diseases including myocardial infarction, stroke and cancer.^11–13 Inflammation induced by exposure to air pollution contributes to some adverse health effects.^14–17 Similar to the effects of air pollution, a proinflammatory response has been associated with appendicitis.^18–20We conducted a case–crossover study involving a population-based cohort of patients admitted to hospital with appendicitis to determine whether short-term increases in concentrations of selected air pollutants were associated with hospital admission because of appendicitis.     

大气污染规制对城市空气污染的防治成效——基于准实验分析

以2003年实施的大气污染防治重点城市政策为准自然实验,运用双重差分模型从区域层面分析了大气污染规制对城市空气污染治理的影响,研究发现：（1）大气污染规制在1%的显著性水平下降低了重点城市的工业二氧化硫排放强度,工业二氧化硫排放量以及城市PM2.5年均浓度值。（2）大气污染防治重点城市政策实施后的9年时间内有效减少了12215.8万t城市工业二氧化硫排放量,并且使得城市PM2.5年均浓度改善2.97μg/m3,下降比分别达到了36.2%和8.5%,平均每年减少了3.7%的城市工业二氧化硫排放量并降低0.944%的城市PM2.5浓度值。（3）大气污染防治重点城市政策对于城市空气污染治理主要是通过减少能源消耗量、增加城市污染治理力度、促进规制地区产业结构转型升级和提升生产技术水平等渠道予以实现。     

Patterns in air pollution as model for the physical basis for olfactory navigation in pigeon homing

Spatial distribution and temporal variability of air pollution were used as a model to describe the stability and predictability of the distribution of airborne substances, postulated by some to be used by homing pigeons to navigate. If the man-made substances reflect the distributional characteristics of natural airborne substances, navigation based on airborne substances is unlikely to be possible.     

Fungal content of air samples from some asthmatic childrens’ homes in Mexico City

Fungal particles can be considered a potential risk factor in children causing asthma, rhinitis, and allergy. However, a direct relationship between mold exposure and respiratory symptoms is difficult to establish, particularly if volumetric results are not well documented, as is often the case in Mexico. In order to assess mold exposure in some asthmatic childrens’ homes, eight asthmatic children were selected. For each child, lung function was measured by spirometry and the flow expiratory volume drop in the first second (FEV₁) as well as the CVF were estimated at 5, 10 and 15 min, after a running period on a treadmill. Exercise induced asthma (EIA) was defined as a FEV₁ drop <10% or FEV₁/CVF drop >10%. Atopy was estimated by skin testing of allergen extracts. Each room was volumetrically sampled using Burkard Personal samplers, every week for a month and with different degrees of activity. Fungal composition was mostly dominated by allergenic molds, spores smaller than 10 μm and non-seasonal molds. Concentrations ranged from 0 to 2087 CFU/m³ and 102 553–29 522 200 spores/m³, being significantly higher in indoor air, but the differences between rooms or weeks were not significant, either for CFUs (P>0.27) or for total particles (P>0.80). In general, mold counts were dominated byPenicillium spp. andCladosporium spp. especiallyP. aurantiogriseum andC. cladosporioides. We observed that the median concentration values were in general higher for children with exercise induced asthma (EIA). But the differences were significant only for EIA and degree, of asthma particularly for total (P=0.038), mycotoxin producers (P<0.009), seasonal molds (P<0.006) andPenicillium spp. (P=0.012). Total spore counts showed the highest median values in children without EIA, moderate asthma degree and no atopy. Significant differences were found for almost all spore, type groupings when comparing the presence of EIA (P<0.05) or asthma degree categories (P<0.030), but no differences were observed for atopy (P>0.21). We conclude that respiratory symptoms as described by EIA, asthma severity and atopy may give a good correlation with fungal concentrations and especially comparisons based on their physical and chemical properties.     

Effect of air traffic pollution on seed quality characteristics of Pinus brutia

This study was undertaken to examine to what degree traffic air pollution affect the reproductive material (the seeds) of Pinus brutia. The study focused on the investigation of the seeds morphological characteristics and physiological attitudes as well as heavy metal concentrations of P. brutia trees grown close the ring-road of Thessaloniki (Greece's second biggest city), polluted by heavy traffic conditions, and how these characteristics are changed with the distance from the pollution source. A sampling procedure was established for seed collection from various distances from the pollution source. Seeds were properly prepared, measured for their morphological characteristics and heavy metal concentrations, as well as for their physiological behaviour (germination and viability). Analysis of the results showed that even though there were no significant differences in seed heavy metal concentrations, and only few in seed morphological characteristics, related to the distance from the traffic pollution source, there was a significant alteration of physiological behaviour for the seeds originated closed to the traffic. All the seed collected close to the ring-road (sample distances 0 and 30 m from the road) were unable to germinate, even those subjected to pre-treatments and repeated germination trials over longer duration, while those collected from distances over 100 m from the ring-road showed a common germination behaviour.     

Escherichia coli in settled-dust and air samples collected in residential environments in Mexico City.

Escherichia coli, an important indicator of the presence of fecal material, was isolated from indoor and outdoor environments in Mexico City. The heterogeneity of E. coli was represented by 89 serotypes, most of them coming from settled-dust indoor samples; 21% of them presented antibiotic multiresistance. The numbers of plasmids were higher among the antibiotic-resistant strains. The results of this study suggest that intestinal infections produced by environmental strains could be of more epidemiological impact than previously thought.     

Impact of air pollution on pulmonary function and respiratory symptoms in children. Longitudinal repeated-measures study

Background

Poor adherence with prescribed asthma medication is a major barrier to positive treatment outcomes. This study was designed to determine the effect of a once-daily administration of mometasone furoate administered via a dry powder inhaler (MF-DPI) on treatment adherence compared with a twice-daily administration.

Methods

This was a 12-week open-label study designed to mimic an actual clinical setting in patients ≥12 years old with mild-to-moderate persistent asthma. Patients were randomized to receive MF-DPI 400 μg once-daily in the evening or MF-DPI 200 μg twice-daily. Adherence was assessed primarily using the number of actual administered doses reported from the device counter divided by the number of scheduled doses. Self-reports were also used to determine adherence. Health-related quality of life, healthcare resource utilization, and days missed from work or school were also reported.

Results

1233 patients were randomized. The mean adherence rates, as measured by the automatic dose counter, were significantly better (P < 0.001) with MF-DPI 400 μg once-daily in the evening (93.3%) than with MF-DPI 200 μg twice-daily (89.5%). Mean adherence rates based on self-reports were also significantly better (P < 0.001) with MF-DPI 400 μg QD PM (97.2%) than with MF-DPI 200 μg twice-daily (95.3%). Adherence rates were lower in adolescents (12-17 years old). Health-related quality of life improved by 20% in patients using MF-DPI once-daily in the evening and by 14% in patients using MF-DPI twice-daily. Very few (<8%) patients missed work/school.

Conclusion

Mean adherence rates were greater with a once-daily dosing regimen of MF-DPI than with a twice-daily dosing regimen. This trial was completed prior to the ISMJE requirements for trial registration.     

Perspectives in chronobiology of air pollution

In a series of experiments, male and female Sprague Dawley rats, kept in light (L) from 06(00) to 18(00) alternating with darkness (LD 12:12) inhaled different concentrations of carbon monoxide (50-1,700 ppm) at each of two test times, 12 h apart. A decrease in flow of CO2 (VCO2) resulting from CO inhalation was greater in the active dark (D) than resting light (L) span. Experimental hypoxic mortality of male and female mice also shows circadian variations, being greater in the D than in the L span. Moreover, a difference of mortality was observed betwen hypoxic exposures performed at 12(00) (in LD or DL) and hypoxic exposures performed at 00(00) (in LD or DL). Such results await tests of any extent to which they model responses of human beings to air pollution. In human beings any external environmental circadian, circaseptan and circannual variations in air pollution as such may serve to variable extent as socioeconomic synchronizers of innate rhythms with a corresponding frequency, rather than as solely generators of time patterns in any physiopathologic response to air pollution.     

Effect of industrial air pollution on wild plant seed germination and seedling growth

Germination of the following wild plant seeds was studied: bilberry (Vaccinium myrtillus L.), cowberry (V. vitis-idaea L.), bog bilberry (V. uliginosum L.), black crowberry (Empetrum hermaphroditum Hagerup), bearberry (Arctostaphylos uva-ursi (L.) Spreng.), bunchberry (Chamaepericlymenum suecicum (L.) Aschers. et Graebn.), cottongrass (Eriophorum polystachion L.), goldenrod (Solidago lapponica With.), fireweed (Chamaenerion angustifolium (L.) Scop.), marsh cinquefoil (Comarum palustre L.), cloudberry (Rubus chamaemorus L.), and Scots pine (Pinus sylvestris L.). The seeds were collected at different distances from the source of industrial air pollution (Severonickel smelter complex, Murmansk region). The task was the assessment of potential possibility of restoring corrupted north forest plant communities via seed propagation. By the response of reproductive structures to stressor, investigated species were divided into 3 groups: tolerant (members of the genus Vaccinium and Ch. angustifolium); moderately tolerant (C. palustre, E. polystachion, A. uva-ursi, and R. chamaemorus); and sensitive (P. sylvestris, E. hermaphroditum, and S. lapponica). Laboratory seed germinability of Vaccinium species was high (> 90%) regardless of the levels of Ni and Cu accumulation in the seeds and the index of technogenic load, whereas this index in E. hermaphroditum and P. sylvestris seeds was significantly reduced with the increase in the heavy metal contents in the seeds. The greenhouse experiments with the seeds of three Vaccinium species collected in the background area and in the zone of the highest pollution and germinated on the forest litter from the same sites and observation for seedling development allow us to conclude that a potential possibility of these species to seed propagation are not limited by their seed viability even under conditions of the highest technogenic load. In sites of environment pollution, the high metal content in the upper soil layer is the main factor limiting plant seed propagation.