Risks of preterm birth and low birth weight and maternal exposure to NO2/PM2.5 acquired by dichotomous evaluation: a systematic review and meta-analysis.

No consistent results from past studies have been found on the relationship between the effects of air pollutant exposure, preterm birth (PTB) and low birth weight (LBW) in fetuses. This study aimed to analyze the impact of high concentrations of air pollutants on the health outcomes of fetuses, especially regarding PTB and LBW. This study used keywords related to air pollutants, pregnancy, and birth outcomes, to search the literature within the databases of the Cochrane Library, PubMed, and Embase, which were published as of July 26, 2022. A total of 24 studies were included in this meta-analysis. This meta-analysis revealed that nitrogen dioxide (NO2) exposure throughout pregnancy was associated with an increased risk of PTB. Maternal exposure to PM2.5 (particulate matter sized less than 2.5 µm) during gestation was associated with the risk of LBW. The findings of this meta-analysis provide an important foundation for evaluating the relationship between exposure of air pollutants and fetal birth outcomes in countries with severe air pollution in the future.

An aerosol inhalation monitor would improve the accuracy of checklist assessment in drug inhalation techniques.

BACKGROUND: Checklists are usually employed to assess the inhalation techniques in patients, but partial techniques are difficult to evaluate visually. This study aimed to assess the checklist validity and an agreement between checklists and an aerosol inhalation monitor (AIM) assessments. METHODS: This study used a checklist and an AIM to evaluate the participants' inhalation techniques with a pressurized metered-dose inhaler (MDI) and two dry powder inhalers (DPIs). The kappa (κ) coefficient, prevalence-adjusted and bias-adjusted κ (PABAK), sensitivity, specificity, positive predictive value, and negative predictive value were all calculated to determine the agreement between the checklist and AIM in an MDI and DPIs with different inhalation technique steps. RESULTS: The checklist and AIM exhibited poor agreement in the MDI for actuation and inhalation time, and a moderate agreement for inspiratory flow. The fair agreement was observed in DPIs for inspiratory flow between the checklist and AIM. The steps of holding breath in MDI and DPIs were highly correlated between both assessments. The lowest accuracy evaluated with an AIM was found in the step of actuation and inhalation time in the MDI and in the inspiratory flow step in DPIs. CONCLUSION: The checklist tended to overestimate the accuracy of critical techniques including the actuation and inhalation time in MDIs and the inspiratory flow in DPIs. Thus, the AIM device can be used as an objective auxiliary tool to assess and quantify the specific steps of inhalation technique for the users with MDI and DPIs.

Use of urinary hippuric acid and o-/p-/m-methyl hippuric acid to evaluate surgical smoke exposure in operating room healthcare personnel.

Toluene and xylene are common components of surgical smoke, whereas hippuric acid (HA) and methylhippuric acid (MHA) are the products of toluene and xylene metabolism in humans, respectively. HA and MHA can be used as indicators to evaluate the exposure hazards of toluene and xylene. In this study, we used liquid chromatography tandem mass spectrometry (LC-MS/MS) to simultaneously analyze the HA, o-/m-/p-MHA, and creatinine contents in the urine of healthcare personnel. Concentrations of HA and o-/m-/p-MHAs were normalized to those of creatinine and used to analyze urine samples of 160 operating room (OR) healthcare personnel, including administrative staff, surgical nurses, nurse anesthetists, and surgeons. The results showed that the five analytes could be accurately separated and exhibited good linearity (r > 0.9992). The rate of recovery was between 86% and 106%, and the relative standard deviation was less than 5%. Urine from administrative staff presented the highest median concentration of hippuric acid (0.25 g/g creatinine); this was significantly higher than that found in the urine of surgeons (0.15 g/g). The concentrations of urinary o-/m-/p-MHAs in surgical nurses were higher than those in administrative staff, nurse anesthetists, and surgeons. Furthermore, the type, sex, and age of healthcare personnel were associated with changes in urine HA and o-/m-/p-MHA concentrations. Healthcare personnel should be aware of the risk of exposure to surgical smoke.

The association between maternal exposure to outdoor air pollutants, inflammatory response, and birth weight in healthy women.

Increased maternal inflammatory response has been noted in women with pregnancies complicated by preterm birth and small-for-gestational age infants. However, the association between gestational exposure to air pollutants, maternal inflammatory response, and fetal growth remains unclear. In this study, we aimed to investigate the association between exposure to air pollutants during pregnancy and the concentration of inflammatory indicators in maternal and fetal circulations, as well as fetal growth. We recruited 108 healthy pregnant women living in northern (n = 55) and southern (n = 53) areas of Taiwan and prospectively collected information of exposure to outdoor air pollutants throughout gestation. Maternal blood from each trimester and umbilical cord blood after delivery were collected and analyzed for inflammatory indicators including high sensitivity C-reactive protein (hs-CRP), interleukin-1ß (IL-1ß), and tumor necrosis factor (TNF)-α. Our results showed that exposure to particulate matter less than or equal to 10 µm (PM10) and ozone (O3) during the first trimester had a direct effect on reduction of birth weight, but the direct effect of PM10 mediated by hs-CRP and the direct effect of O3 mediated by TNF-α on fetal birth weight were not significant. Exposure to PM10 and PM2.5 during the second and third trimesters also directly affected birth weight. Furthermore, exposure to sulfur dioxide (SO2) caused changes in the concentrations of TNF-α in maternal blood during the second trimester, which subsequently resulted in reduced fetal weight. Together, these results indicate that exposure to air pollutants may cause both direct and indirect effects on the reduction of fetal weight.

Sources and components of volatile organic compounds in breast surgery operating rooms.

OBJECTIVES: The composition and concentration distribution of volatile organic compounds (VOCs) in surgical smoke had seldomly been reported. This study aimed to investigate the profile of VOCs and their concentration in surgical smoke from breast surgery during electrocautery in different tissues, electrosurgical units, and electrocautery powers. METHODS: Thirty-eight surgical smoke samples from 23 patients performed breast surgery were collected using evacuated stainless steel canisters. The concentrations of 87 VOCs in surgical smoke samples were analyzed by gas chromatography-mass spectrometry. The human tissues, electrosurgical units, and electrocautery power were recorded. RESULTS: The median level of total VOCs concentrations in surgical smoke samples from mammary glands (total VOCs: 9953.5 ppb; benzene: 222.7 ppb; 1,3-butadiene: 856.2 ppb; vinyl chloride: 3.1 ppb) using conventional electrosurgical knives were significantly higher than that from other tissues (total VOCs: 365.7-4266.8 ppb, P < 0.05; benzene: 26.4-112 ppb, P < 0.05; 1,3-butadiene: 15.6-384 ppb, P < 0.05; vinyl chloride: 0.6-1.8 ppb, P < 0.05) using different electrosurgical units. A high methanol concentration was found in surgical smoke generated during breast surgery (641.4-4452.5 ppb) using different electrosurgical units. An electrocautery power of ≥ 27.5 watts used for skin tissues produced a higher VOCs concentration (2905.8 ppb). CONCLUSIONS: The surgical smoke samples collected from mammary glands using conventional electrosurgical knives had high VOCs concentrations. The carcinogens (including benzene, 1,3-butadiene, and vinyl chloride) and methanol were found in the surgical smoke samples from different electrosurgical units. The type of electrosurgical unit and electrocautery power used affected VOCs concentrations in surgical smoke.

Outdoor air pollutants exposure associated with pulmonary function and EBC pH value in atopic asthmatic and non-asthmatic children.

OBJECTIVE: Air pollution is associated with the prevalence of respiratory diseases. This study aimed to evaluate the impacts of outdoor air pollutants and indoor Dermatophagoides pteronyssinus 1 (Der p 1) exposure on levels of fractional exhaled nitric oxide (FeNO), exhaled breath condensate (EBC) pH, and pulmonary function in atopic children. METHODS: This study recruited 59 atopic mild-to-moderate asthmatic children and 23 atopic non-asthmatic children. Data on personal characteristics, FeNO, EBC pH, and pulmonary function were collected. Group 1 allergens of Der p 1 were measured on the tops of mattresses and on bedroom floors in the children's homes, and outdoor air pollutant concentrations were estimated from air quality monitoring stations, using the ordinary kriging method. RESULTS: Exposure levels of outdoor air pollutants, except for particulate matter (PM)2.5, for the recruited children met outdoor air quality standards set by the Taiwan Environmental Protection Agency. The lag effect of outdoor PM10 exposure was negatively associated with the forced expiratory volume in one second (FEV1) [(Lag 1: ß=-0.771, p = 0.028), and O3 (Lag 1-7: ß=-2.02, p = 0.04, Lag 1-28: ß=-3.213, p = 0.029)]. Median pulmonary function parameters differed significantly in forced vital capacity (FVC) (p = 0.004) and FEV1 (p = 0.024) values between atopic asthmatic and non-asthmatic children. No association was found between the FeNO/EBC pH level and exposure to Der p 1 allergen and air pollutants in the recruited children. CONCLUSIONS: Outdoor PM10 and O3 exposure was associated with reduction in FEV1 in atopic asthmatic and non-asthmatic children.

Hypertonic saline enhances the efficacy of aerosolized gentamicin against Pseudomonas aeruginosa.

Aerosol inhalation is a promising strategy for the delivery of antibiotic agents. The efficacy of antibiotic treatment by aerosol inhalation is reduced by the formation of microbial biofilms in the respiratory system and excessive airway mucus build-up. Various approaches have been taken in order to overcome this barrier. In this in vitro study, we used hypertonic saline (7%, by weight), a low cost Food and Drug Administration-approved reagent, as an aerosol carrier to study its effects with the antibiotic, gentamicin, on the most common respiratory opportunistic pathogen, Pseudomonas aeruginosa, present in the mucus. The results indicated that the hypertonic saline aerosol containing gentamicin, a low cost antibiotic, significantly eliminated biofilm growth by ~3-fold, compared to the regular saline aerosol containing gentamicin. In addition to enhancing the penetration efficiency of drug molecules by 70%, bacterial motility also decreased (~50%) after treatment with aerosolised hypertonic saline. In conclusion, our results demonstrate that hypertonic saline can significantly enhance the efficacy of antibiotic aerosols, which may contribute to the current use of inhaled therapeutic compounds.

Removal efficiency of central vacuum system and protective masks to suspended particles from dental treatment.

BACKGROUND: High levels of suspended particulate matters (PMs) and bioaerosols are created by dental procedures. The present study aimed to evaluate the size and concentration of PMs produced by drilling and grinding teeth, and to assess the efficiency of central vacuum system and protective masks for the removal of PMs. METHODS: A total of 20 extracted permanent teeth were collected. A novel experimental system and particle counter were used to evaluate the PMs produced by dental procedures and the PM removal efficiency of a central vacuum system and surgical/N95 masks. RESULTS: The number concentration of total PMs produced by drilling and grinding teeth was significantly higher than the indoor background concentration. The average aerodynamic diameter of particle was generally less than 1 µm. The average number concentration of ultrafine particles was 2.1x1011 particles/m3 during tooth drilling and grinding. The efficiency of the central vacuum system was 35.74% for PM≥0.5 and 35.41% for PM10. For PM≥0.5, the ratios of inside and outside masks were 0.8-1.34 without vacuum and 1.18-1.36 with vacuum. No difference was found with the use of surgical/N95 masks during dental therapy, with or without vacuum use. CONCLUSIONS: High levels of PMs were found during tooth drilling and grinding procedures, especially among PM1. The PM removal efficiency of a central vacuum system and surgical/N95 masks were limited.

Size Distribution of Colistin Delivery by Different Type Nebulizers and Concentrations During Mechanical Ventilation.

Although aerosol delivery through mechanical ventilators has been used to administer various medications, little is known of administration with colistin. This in vitro evaluation aimed to evaluate size distribution of colistin delivery by different types of nebulizers and concentrations during mechanical ventilation. Colistin methanesulfonate (colistin) for injection was dissolved in 6 mL of distilled water to produce a low concentration (L; 156 mg) and a high concentration (H; 312 mg). A dose volume of 6 mL was placed in a vibrating mesh nebulizer (VMN) and a jet nebulizer (JN). The inhaled mass (mean ± SD) of the VMN-L (53.80 ± 14.79 mg) was greater than both the JN-L (19.82 ± 3.34 mg, P = 0.001) and JN-H (31.72 ± 4.48 mg, P = 0.017). The nebulization time of the VMN-L (42.35 ± 2.30 min) was two times longer than the JN-L (21.12 ± 0.8 min) or JN-H (21.65 ± 0.42 min; P < 0.001). The mass median aerodynamic distal to the endotracheal tube was within a similar range at 2.03 to 2.26 µm (P = 0.434), independent of neb or formulation concentration. In conclusion, the VMN-L yields greater inhaled mass than the JN with either concentration. Therefore, a standard nominal dose of colistin results in a higher delivered dose during mechanical ventilation with a VMN compared with a JN and may be considered the preferred device. If JN must be used, multiple doses of low concentration colistin may compensate for poor delivery performance.

Effectiveness of engineering interventions in decreasing worker exposure to metalworking fluid aerosols.

Machine industry accounts for the highest proportion of primary industry in Taiwan. Long-term exposure to metalworking fluid aerosols may pose significant threats to the health of workers. The aims of this study were to verify the efficacy of intervention methods in reducing airborne bacterial concentrations as well as effects on aerosol particle size distribution. This study evaluated airborne bacterial concentrations in a large precision machinery factory in Taichung, Taiwan, before and after the implementation of intervention methods. The installation of local exhaust systems and improvement of the operation mode were used as intervention methods. Concentration and size distribution of bacteria in the metal working environment were assessed using Andersen one-stage and six-stage viable impactors, respectively. The analytical results indicate that most bacterial concentrations were less than the recommended concentrations in the indoor air quality standards (500 CFU/m3) proposed by the United States Association of Advancing Occupational and Environmental Health (US ACGIH) before the installation of local exhaust systems. There was no significant difference in bacterial concentrations before and after the installation of the local exhaust and the intervention effect on reducing bacterial exposure was not as expected. The bacterial concentrations were significantly lowered in the Z region after improving the operation mode. The particle size of bioaerosols <7.0 µm was also substantially reduced. Improper operation modes are likely to expose employees to higher concentrations of bacteria within a short time period. It recommends adjusting the metal processing methods and proper use of air spray guns for decreasing high airborne bacterial concentrations exposure.

Mother-infant interaction quality and sense of parenting competence at six months postpartum for first-time mothers in Taiwan: a multiple time series design.

BACKGROUND: For first-time mothers, not knowing how to interact with newborn infants increases anxiety and decreases the quality of the parent-infant interactions. A substantial lack of interactional knowledge can ultimately limit the adjustments necessary for a stable transition into motherhood. This study investigated how postpartum parenting education influenced first-time mothers' mother-infant interaction quality and parenting sense of competence. METHODS: Eighty-one healthy first-time-mother and infant dyads were recruited. The control group (n = 40) received postpartum care based on the medical and cultural norms practiced in Taiwan, while the experimental group (n = 41) received, on top of typical care, education by way of a 40-min videotape on infant states, behaviors, and communication cues, as well as a handout on play practices. Data were collected at five points: within the first week, and during follow-ups in the first, second, third, and sixth months after birth. We administered the Chinese versions of the Parenting Sense of Competence Scale and Edinburgh Perinatal Depression Scale, and used the Nursing Child Assessment Teaching Scale to score videotaped mother-infant interactions. RESULTS: We observed an increase in the quality of mother-infant interaction within the experimental group only. Furthermore, at the five assessment points, we observed no significant changes in perceived parenting competence. Among all subjects, there were correlations between postpartum depression scores, parenting competency, and quality of mother-infant interaction. CONCLUSIONS: Our results indicate that first-time mothers in Taiwan who are provided with extra education on infants' abilities and how to effectively play with infants are likely to exhibit improvements in quality of interaction.

Potential risk for bacterial contamination in conventional reused ventilator systems and disposable closed ventilator-suction systems.

BACKGROUND: Few studies have investigated the difference in bacterial contamination between conventional reused ventilator systems and disposable closed ventilator-suction systems. The aim of this study was to investigate the bacterial contamination rates of the reused and disposable ventilator systems, and the association between system disconnection and bacterial contamination of ventilator systems. METHODS: The enrolled intubated and mechanically ventilated patients used a conventional reused ventilator system and a disposable closed ventilator-suction system, respectively, for a week; specimens were then collected from the ventilator circuit systems to evaluate human and environmental bacterial contamination. The sputum specimens from patients were also analyzed in this study. RESULTS: The detection rate of bacteria in the conventional reused ventilator system was substantially higher than that in the disposable ventilator system. The inspiratory and expiratory limbs of the disposable closed ventilator-suction system had higher bacterial concentrations than the conventional reused ventilator system. The bacterial concentration in the heated humidifier of the reused ventilator system was significantly higher than that in the disposable ventilator system. Positive associations existed among the bacterial concentrations at different locations in the reused and disposable ventilator systems, respectively. The predominant bacteria identified in the reused and disposable ventilator systems included Acinetobacter spp., Bacillus cereus, Elizabethkingia spp., Pseudomonas spp., and Stenotrophomonas (Xan) maltophilia. CONCLUSIONS: Both the reused and disposable ventilator systems had high bacterial contamination rates after one week of use. Disconnection of the ventilator systems should be avoided during system operation to decrease the risks of environmental pollution and human exposure, especially for the disposable ventilator system. TRIAL REGISTRATION: ClinicalTrials.gov PRS / NCT03359148.

Effect of ventilation rate on air cleanliness and energy consumption in operation rooms at rest.

The interrelationships between ventilation rate, indoor air quality, and energy consumption in operation rooms at rest are yet to be understood. We investigate the effect of ventilation rate on indoor air quality indices and energy consumption in ORs at rest. The study investigates the air temperature, relative humidity, concentrations of carbon dioxide, particulate matter (PM), and airborne bacteria at different ventilation rates in operation rooms at rest of a medical center. The energy consumption and cost analysis of the heating, ventilating, and air conditioning (HVAC) system in the operation rooms at rest were also evaluated for all ventilation rates. No air-conditioned operation rooms had very highest PM and airborne bacterial concentrations in the operation areas. The bacterial concentration in the operation areas with 6-30 air changes per hour (ACH) was below the suggested level set by the United Kingdom (UK) for an empty operation room. A 70% of reduction in annual energy cost by reducing the ventilation rate from 30 to 6 ACH was found in the operation rooms at rest. Maintenance of operation rooms at ventilation rate of 6 ACH could save considerable amounts of energy and achieve the goal of air cleanliness.

Aerosol delivery during spontaneous breathing with different types of nebulizers- in vitro/ex vivo models evaluation.

BACKGROUND: Nebulizers for spontaneous breathing have been evaluated through different study designs. There are limitations in simulated bench models related to patient and nebulizer factors. The aim of this study was to determine the correlation of inhaled drug mass between in vitro and ex vivo studies by testing aerosol deposition of various types of nebulizers. METHODS: Ten healthy subjects were recruited to receive aerosol therapy with five nebulizers in random order: 1) a jet nebulizer (JN); 2) a breath-enhanced nebulizer (BEN); 3) a manually triggered nebulizer (MTN), 4) a breath-actuated nebulizer (BAN), and 5) a vibrating mesh nebulizer (VMN) with valved-adapter. A unit dose of salbutamol containing 5 mg in 2.5 mL was placed into the nebulizer and administered for 10 min. For the ex vivo study, minute ventilation of healthy subjects was recorded for 1 min. For the in vitro study a breathing simulator was utilized with adult breathing patterns. Aerosolized drug from the nebulizers and the accessory tubes was captured using inspiratory and expiratory collecting filters. Captured drug was eluted, measured and expressed as inhaled and exhaled mass using spectrophotometry at a wavelength of 276 nm. RESULTS: 10 healthy subjects were recruited, aged 20.8 ±â€¯0.7 years old, with a mean height of 166.2 ±â€¯9.2 cm and weight of 64.7 ±â€¯12.4 kg. There was no significant difference in the inhaled drug dose between the JN and BEN (15.0 ±â€¯1.94% and 17.74 ±â€¯2.65%, respectively, p = .763), yet the inhaled doses were lower than the other three nebulizers (p < .001). The VMN delivered greater inhaled dose than the other four nebulizers (p < .01). The respiratory rate of the cohorts was significantly correlated with the inhaled drug dose. For the in vitro model, the JN delivered a lower inhaled dose (11.6 ±â€¯1.6, p < .001) than the other nebulizers, whereas the MTN and BAN deposited significantly lower exhaled doses (1.7 ±â€¯0.4 and 2.7 ±â€¯0.2, respectively, p < .001). The VMN demonstrated a greater drug dose with the in vitro study than the ex vivo model (44.0 ±â€¯0.9% and 35.5 ±â€¯6.3% respectively, p = .003), whereas the JN in the ex vivo model resulted in a greater inhaled drug dose (15.0 ±â€¯1.9% for ex vivo vs 11.6 ±â€¯1.6% for in vitro, p = .008). CONCLUSIONS: These in vitro/ex vivo model comparisons of nebulizers performance indicated that breath-related nebulizers can be estimated using an in vitro model; however, the JN and VMN delivered inhaled drug mass differed between models. There was a significant correlation between respiratory rate and inhaled mass, and the inhaled drug dose generated by VMN correlated with minute ventilation. This study demonstrated that the VMN produced greater inhaled drug dose and lowest residual dose, whereas the BEN, BAN, and MTN produced lower exhaled drug dose in both in vitro and ex vivo models.

Size distribution of salbutamol/ipratropium aerosols produced by different nebulizers in the absence and presence of heat and humidification.

BACKGROUND: Few studies have evaluated the size distribution of inhaled and exhaled aerosolized drugs, or the effect of heated humidification on particle size and lung deposition. The present study evaluated these aspects of bronchodilator (salbutamol/ipratropium) delivery using a lung model in the absence and presence of heat and humidification. METHODS: We positioned filters to collect and measure the initial drug, inhaled drug, and exhaled drug. Particle size distribution was evaluated using an 8-stage Marple personal cascade impactor with 0.2-µm polycarbonate filters. RESULTS: A greater inhaled drug mass was delivered using a vibrating mesh nebulizer (VMN) than by using a small volume nebulizer (SVN), when heated humidifiers were not employed. When heated and humidified medical gas was used, there was no significant difference between the inhaled drug mass delivered by the VMN and that delivered by the SVN. A significantly greater mass of inhaled 1.55-µm drug particles was produced by the VMN than with the SVN, under heated and humidified conditions. However, the mass median aerodynamic diameters (MMADs) of the aerosolized drug produced by the SVN and VMN did not differ significantly under the same conditions. CONCLUSIONS: The VMN produced more fine particles of salbutamol/ipratropium, and the drug particle size clearly increased in the presence of heat and humidification.

High total volatile organic compounds pollution in a hospital dental department.

Bioaerosols produced by dental procedures may affect indoor air quality and cause infections in dental healthcare workers. To provide air quality data that can be used to protect dental healthcare workers, this study evaluated the air quality and its influencing factors in the dental department of the Chang Gung Memorial Hospital in Taiwan. The study was a cross-sectional study design. Indoor air quality (IAQ) evaluations were conducted in six locations: pediatric dentistry, craniofacial orthodontic dentistry, periodontal dentistry, and general practice dentistry, instrument washing room, and patient waiting area. The measured air quality parameters included temperature, relative humidity, and concentrations of CO2, total volatile organic compounds (TVOCs), suspended particulate matter (PM), and bacteria. TVOCs concentrations at all six sampling stations were found to exceed the indoor air quality standards prescribed by the Taiwan Environmental Protection Agency. The highest concentrations of atmospheric PM10, PM2.5, and PM1 were found in the periodontal dentistry department, while the lowest concentrations occurred in the patient waiting area. The detection rate for Gram-positive bacteria was highest in the pediatric department (25%) and lowest in the instrument washing room (9%). Micrococcus luteus and Bacillus cereus were the primary pathogens detected. The dental departments of the hospital had a serious TVOCs pollution. The air quality of dental departments deserves long-term surveillance and attention.

Urban air pollution and meteorological factors affect emergency department visits of elderly patients with chronic obstructive pulmonary disease in Taiwan.

Both air pollution and meteorological factors in metropolitan areas increased emergency department (ED) visits from people with chronic obstructive pulmonary disease (COPD). Few studies investigated the associations between air pollution, meteorological factors, and COPD-related health disorders in Asian countries. This study aimed to investigate the relationship between the environmental factors and COPD-associated ED visits of susceptible elderly population in the largest Taiwanese metropolitan area (Taipei area, including Taipei city and New Taipei city) between 2000 and 2013. Data of air pollutant concentrations (PM10, PM2.5, O3, SO2, NO2 and CO), meteorological factors (daily temperature, relative humidity and air pressure), and daily COPD-associated ED visits were collected from Taiwan Environmental Protection Administration air monitoring stations, Central Weather Bureau stations, and the Taiwan National Health Insurance database in Taipei area. We used a case-crossover study design and conditional logistic regression models with odds ratios (ORs), and 95% confidence intervals (CIs) for evaluating the associations between the environmental factors and COPD-associated ED visits. Analyses showed that PM2.5, O3, and SO2 had significantly greater lag effects (the lag was 4 days for PM2.5, and 5 days for O3 and SO2) on COPD-associated ED visits of the elderly population (65-79 years old). In warmer days, a significantly greater effect on elderly COPD-associated ED visits was estimated for PM2.5 with coexistence of O3. Additionally, either O3 or SO2 combined with other air pollutants increased the risk of elderly COPD-associated ED visits in the days of high relative humidity and air pressure difference, respectively. This study showed that joint effect of urban air pollution and meteorological factors contributed to the COPD-associated ED visits of the susceptible elderly population in the largest metropolitan area in Taiwan. Government authorities should review existing air pollution policies, and strengthen health education propaganda to ensure the health of the susceptible elderly population.

Urban Air Pollution in Taiwan before and after the Installation of a Mass Rapid Transit System.

Urbanization causes air pollution in metropolitan areas, coupled with meteorological factors that affect air quality. Although previous studies focused on the relationships of urbanization, air pollution, and climate change in Western countries, this study evaluated long-term variations of air quality and meteorological factors in Taiwanese metropolitan areas (Taipei area, Taichung City, and Kaohsiung City) and a rural area (Hualien County) between 1993 and 2012. The influence of a mass rapid transit (MRT) system on air quality was also evaluated. Air pollutant concentrations and meteorology data were collected from Taiwan Environmental Protection Administration (TEPA) air monitoring stations and Central Weather Bureau stations in the surveyed areas, respectively. Analyses indicate that levels of air pollution in metropolitan areas were greater than in the rural area. Kaohsiung City had the highest levels of O, SO, and particulate matter 2.5 or 10 µm in diameter (PM and PM). Clear downward trends for CO, NO, PM, PM, and especially SO concentrations were found in the surveyed areas, whereas O showed no decrease. Both O and PM concentrations showed similar bimodal seasonal distributions. Taiwan's air quality has improved significantly since 1993, indicating the effectiveness of promoting air pollution strategies and policies by the TEPA. Air pollution had an obvious improvement in Taipei area after the MRT system began operations in 1996. Because global climate may potentially affect urban air pollution in Taiwan, further study to clarify the mechanisms by which air pollution may affect human health and other biological effects is warranted.

The relationships among Dermatophagoides pteronyssinus exposure, exhaled nitric oxide, and exhaled breath condensate pH levels in atopic asthmatic children.

This study examined seasonal changes in indoor Dermatophagoides pteronyssinus 1 (Der p 1)/Blattella germanica 1 (Bla g 1) antigen concentrations in the homes of atopic asthmatic and atopic nonasthmatic children. Possible associations between environmental allergen exposure and levels of exhaled breath indices were also evaluated.A total of 38 atopic children were recruited for this cross-sectional study: 22 were asthmatic and 16 were nonasthmatic. Home visits were conducted for indoor air and dust sampling each season. Exhaled nitric oxide (eNO)/spirometric measurements were taken and exhaled breath condensate (EBC) was collected after sampling of the domestic environment.The highest Der p 1 concentrations were on the top of mattresses in the homes of recruited children. The floors of kitchens and living rooms had the highest Bla g 1 concentrations in the homes of atopic asthmatic children. A positive correlation was found between Der p 1 exposure of mattress, bedroom floor, and living room floor and eNO levels in the atopic asthmatic children. The Der p 1 concentrations on the surfaces of mattress and bedroom floor were positively related to high eNO levels in the atopic asthmatic children after adjusting for season. No association was found between Der p 1 exposure and EBC pH values in the recruited children.A positive correlation was found between Der p 1 exposure and high eNO levels in atopic asthmatic children, especially in Der p 1 exposure of mattress and bedroom floor.