Seasonal Disparities of Human Health Risk and Particle-Bound Metal Characteristics Associated with Atmospheric Particles in a Fishery Harbor.

The effects of atmospheric pollution from ship emissions have been considered for several harbors worldwide. The health risk assessment and source apportionment of particle-bound metals in a fishery harbor were investigated in this study. The most abundant metal elements in particulate matter (PM) on all sampling days in three seasons were Fe (280.94 ± 136.93 ng/m3), Al (116.40 ± 71.25 ng/m3), and Zn (110.55 ± 26.70 ng/m3). The ratios of V/Ni were 1.44 ± 0.31, 1.48 ± 0.09 and 1.87 ± 0.06 in PM10, PM2.5, and PM1, respectively. Meanwhile, the ratios higher than 1 indicated that fuel oil combustion from ship emission in fishery harbor. The highest deposits of total particle-bound metals in the human respiratory tract were in the head airway (HA), accounting for 76.77 ± 2.29% of the total particle-bound metal concentration, followed by 5.32 ± 0.13% and 2.53 ± 0.15% in the alveolar region (AR) and tracheobronchial (TB) region, respectively. The total cancer risk (CR) of inhalation exposure to local residents exceeded 10-6. Mean total CR values followed the sequence: autumn (1.24 × 10-4) > winter (8.53 × 10-5) > spring (2.77 × 10-6). Source apportionment of related metal emissions was mobile pollution emissions (vehicle/boat) (37.10-48.92%), metal fumes of arc welding exhaust (19.68-34.42%), spray-painting process (12.34-16.24%), combustion emissions (6.32-13.12%), and metal machining processes (9.04-16.31%) in Singda fishing harbor. These results suggest that proper control of heavy metals from each potential source in fishing harbor areas should be carried out to reduce the carcinogenic risk of adverse health effects.

Rapid synthesis of Ti-MCM-41 by microwave-assisted hydrothermal method towards photocatalytic degradation of oxytetracycline.

This study employed microwave-assisted hydrothermal method to synthesize Ti-MCM-41, which are mesoporous materials with a high surface area and excellent photocatalytic ability. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV-Vis) were employed. The XRD findings showed that Ti-MCM-41 exhibited a peak at 2θ of 2.2°, which was attributed to the hexagonal MCM-41 structure. The BET (Brunauer-Emmett-Teller) results agreed with the TEM findings that Ti-MCM-41 has a pore size of about 3-5nm and a high surface area of 883m(2)/g. FTIR results illustrated the existence of Si-O-Si and Si-O-Ti bonds in Ti-MCM-41. The appearance of Ti 2p peaks in the XPS results confirmed the FTIR findings that the Ti was successfully doped into the MCM-41 structure. Zeta (ζ)-potential results indicated that the iso-electric point (IEP) of Ti-MCM-41 was at about pH3.02. In this study, the photocatalytic degradation of oxytetracycline (OTC) at different pH was investigated under Hg lamp irradiation (wavelength 365nm). The rate constant (K'obs) for OTC degradation was 0.012min(-1) at pH3. Furthermore, TOC (total organic carbon) and high resolution LC-MS (liquid chromatography-mass spectrometry) analyses were conducted to elucidate the possible intermediate products and degradation pathway for OTC. The TOC removal efficiency of OTC degradation was 87.0%, 74.4% and 50.9% at pH3, 7 and 10, respectively. LC-MS analysis results showed that the degradation products from OTC resulted from the removal of functional groups from the OTC ring.

Photocatalytic degradation of Rhodamine B by microwave-assisted hydrothermal synthesized N-doped titanate nanotubes.

Microwave-induced nitrogen-doped titanate nanotubes (NTNTs) were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Zeta potential analysis, specific surface area (SBET), and UV-Visible spectroscopy. TEM results indicate that NTNTs retain a tubular structure with a crystalline multiwall and have a length of several hundred nanometers after nitrogen doping. XRD findings demonstrate that the crystalline structure of NTNTs was dominated by anatase, which is favored for photocatalytic application. The Ti-O-N linkage observed in the XPS N 1s spectrum is mainly responsible for narrowing the band gap and eventually enhancing the visible light photoactivity. FT-IR results demonstrated the existence of H3O⁺, which could be excited by photo-generated holes to form hydroxyl radicals and degrade environmental pollutants. After sintering at 350°C, the UV-Vis absorbance edges of NTNTs significantly shift to the visible-light region, which indicates N atom doping into the nanotubes. Photocatalytic degradation of Rhodamine B (RhB) via NTNTs show good efficiency, with pseudo first-order kinetic model rate constants of 3.7 × 10⁻³, 2.4 × 10⁻³ and 8.0 × 10⁻4 sec⁻¹ at pH3, 7, and 11, respectively.

Volatile hydrocarbon emissions from vehicles and vertical ventilations in the Hsuehshan traffic tunnel, Taiwan.

The concentrations of 56 volatile organic hydrocarbons (VOCs) were measured simultaneously in the southbound bore, the northbound bore and the exhaust air shafts of the Hsuehshan tunnel near Yilan, Taiwan during 2007 and 2008. A total of 60 integrated air samples were collected using stainless steel canisters and analyzed using GC/FID and GC/MS. The highest temperature and lowest relative humidity were observed at the exit of the tunnel owing to the accumulation in the tunnel of waste heat that was exhausted from vehicles. The five most abundant species in all samples were ethylene, acetylene, isopentane, propylene, and toluene. The exit/entrance ratios of total non-methane hydrocarbon (NMHC) concentration were 7.8 and 4.8 for the southbound and northbound bores, respectively. Furthermore, the most abundant species of emission rate (ER) is toluene (21.93-42.89 mg s(-1)), followed by isopentane, ethylene, propylene and 1-butene, with ER ranging from 2.50 to 9.31 mg s(-1) for the three shafts. The ozone formation potential (OFP)/total NMHC ratios in three exhaust air shafts show that the reactivities of these emissions are similar to those of vehicle emissions.

Adverse pulmonary impacts of environmental concentrations of oil mist particulate matter in normal human bronchial epithelial cell.

Airborne oil mist particulate matter (OMPM) is generated during industrial processes such as metalworking and may be associated with pulmonary dysfunction. In this study, we employed the normal human bronchial epithelial BEAS-2B cell line to elucidate the association between pulmonary toxicity and OMPM of 2.5-10 µm, 1.0-2.5 µm and <1.0 µm particle sizes (OMPM10-2.5, OMPM2.5-1.0 and OMPM1.0). We measured OMPM concentrations at a precision machinery factory to estimate lung deposition rates and select realistic environmental concentrations for testing. All OMPMs (1-50 µg/cm2) significantly decreased BEAS-2B cell viability (>38% of control), except for low-dose OMPM1.0 (1 µg/cm2). OMPM10-2.5 and OMPM2.5-1.0, but not OMPM1.0, induced oxidative stress (1.5-4-fold increase compared with the control) and increased the production of proinflammatory cytokines (1.5-3-fold). However, only OMPM1.0 induced pulmonary epithelial barrier dysfunction via depletion of zonula occludens (0.65-0.8-fold) and α1-antitrypsin proteins (0.65-0.8-fold). In conclusion, a higher risk of lung disease was associated with smaller particle size OMPM. Exposure to OMPM1.0 may be a potential risk factor for chronic obstructive pulmonary disease. The evidence also demonstrates that occupational exposure to OMPM may cause pulmonary disease at very low concentrations.

A study of factors affecting moving-forward behavior among people with spinal cord injury.

Enhancing self-efficacy, self-perception, and social support can be an effective way for people with spinal cord injury (SCI) to move forward. The purpose of this study was to explore relationships between "moving-forward behavior" and demographic and disease characteristics, self-efficacy, self-perception, and social support among people with SCI. The study was designed as a descriptive-correlation, cross-sectional study. The participants were selected using cluster random sampling (n = 210) through the Spinal Injury Association in Taiwan. A statistically significant relationship was found between moving-forward behavior and age (t = -2.30, p < .05), self-efficacy (gamma = -0.25, p < .01), and self-perception (gamma = -0.39, p < .01). Age (odds ratio [OR] = 0.964, p < .05) and self-perception (OR = 0.824, p < .05) were both significant predictors of moving-forward behavior.

Emissions of C2 - C12 hydrocarbons in the Hsuehshan tunnel, Taiwan.

The concentrations of 56 hydrocarbons from C2 to C12 were measured simultaneously in the southbound bore, the northbound bore and the exhaust air shafts of the Hsuehshan tunnel near Yilan, Taiwan for 12 days during 2007 and 2008. A total of 60 integrated air samples were collected using stainless steel canisters and analyzed using GC/FID and GC/MS. The five most abundant species in all samples were ethylene, acetylene, isopentane, propylene and toluene. The exit/entrance ratios of total non-methane hydrocarbons (NMHC) concentration were 7.8 and 4.8 for the southbound and northbound bores, respectively. Furthermore, the exhaust from the vertical shafts affects air quality in the neighborhood. The most abundant species of emission rate (ER) was toluene (21.93-42.89 mg/sec), followed by isopentane, ethylene, propylene and 1-butene, with ER ranging from 2.50 to 9.31 mg/sec. The species in the three exhaust air shafts showed that the reactivities of these emissions are similar to those of vehicle emissions. Notably, the control of emissions in the vertical shafts of the vehicle tunnel will be important in the future.

Applying model simulation and photochemical indicators to evaluate ozone sensitivity in southern Taiwan.

Ozone sensitivity was investigated using CAMx simulations and photochemical indicator ratios at three sites (Pingtung City, Chao-Chou Town, and Kenting Town) in Pingtung County in southern Taiwan during 2003 and 2004. The CAMx simulations compared fairly well with the hourly concentrations of ozone. Simulation results also showed that Pingtung City was mainly a volatile organic compounds (VOC)-sensitive regime, while Chao-Chou Town was either a VOC-sensitive or a NOx-sensitive regime, depending on the seasons. Measurements of three photochemical indicators (H2O2, HNO3, and NOy) were conducted, and simulated three transition ranges of H2O2/HNO3 (0.5-0.8), O3/HNO3 (10.3-16.2) and O3/NOy (5.7-10.8) were adopted to assess the ozone sensitive regime at the three sites. The results indicated that the three transition ranges yield consistent results with CAMx simulations at most times at Pingtung City. However, both VOC-sensitive and NOx-sensitive regimes were important at the rural site Chao-Chou Town. Kenting Town, a touring site at the southern end of Taiwan, was predominated by a NOx-sensitive regime in four seasons.

Human health-risk assessment based on chronic exposure to the carbonyl compounds and metals emitted by burning incense at temples.

Health effects resulting from the smoke of carbonyl compounds (aldehydes and ketones) and metal-containing incense particles at temples during incense burning periods were evaluated at temple A (without incense reduction activities) and B (with incense reduction activities), Nantou County, in 2018. The predominant size fractions of particles were PM1, PM1-2.5, and PM2.5-10 at both temples. The total particle mass at temple A was approximately 1.1 times that of temple B due to incense reduction at temple B. The most abundant metal elements in all particle size fractions at both temples were Fe, Al, and Zn. Metal species of incense smoke are divided into three groups by hierarchical cluster analysis and heatmaps, showing higher metal contents in groups PM1, PM18-10, and PM18-2.5 at temple A. In contrast, higher metal contents were observed in PM18-10 and PM2.5-1 at temple B. Most of the carbonyl species were formaldehyde and acetaldehyde, released during incense burning periods, with concentrations ranging from 6.20 to 13.05 µg/m3 at both temples. The total deposited fluxes of particle-bound metals at temples A and B were determined to be 83.00% and 84.82% using the International Commission on Radiological Protection (ICRP) model. Health-risk assessments revealed that the risk values of metals and carbonyls were above recommended guidelines (10-6) at temple A. Since worshippers and staff are exposed to incense burning environments with poor ventilation over a long period, these toxic organic compounds and metals increase health risks in the respiratory tract. Therefore, incense reduction is important to achieve healthy temple environments.

PM2.5 collecting in a tire manufacturing plant affects epithelial differentiation of human umbilical cord derived mesenchymal stem cells by Wnt/ß-catenin pathway.

Mesenchymal stem cells (MSCs) can differentiate into pulmonary epithelial cells by Wnt/ß-catenin pathway and promote lung repair. However, whether fine particulate matter (PM2.5) could affect Wnt pathway and finally reduce the ability of MSCs to differentiate into epithelial cells is still unknown. This study aimed to investigate whether PM2.5 could inhibit the epithelial differentiation of human umbilical cord-derived MSCs cells (hUCMSCs) and the related underlying mechanism. hUCMSCs were incubated with different concentrations of PM2.5. Then, the cell viability, reactive oxygen species level, and single-cell sphere formation were assessed. The underlying mechanism of PM2.5 in epithelial differentiation of hUCMSCs was further evaluated by co-culturing hUCMSCs with A549 cells. Our results demonstrated that PM2.5 exposures could affect the expressions of ß-catenin and lung epithelial markers (zonula occludens-1 (ZO-1); cytokeratins 5 and 19) in the co-cultured hUCMSCs. The Wnt/ß-catenin pathway is involved in regulating the epithelial differentiation of MSCs. As expected, co-treatment with Wnt3a, which is the activator of the Wnt pathway, attenuated the downregulation of lung epithelial markers (ZO-1; cytokeratins 5 and 19) and paracrine factors (keratinocyte growth factor and hepatocyte growth factor) caused by PM2.5. Altogether, these results demonstrated that PM2.5 could affect the epithelial differentiation of hUCMSCs via the Wnt/ß-catenin pathway.

Influence of rice straw burning on the levels of polycyclic aromatic hydrocarbons in agricultural county of Taiwan.

Atmospheric particulate and polycyclic aromatic hydrocarbons (PAHs) size distribution were measured at Jhu-Shan (a rural site) and Sin-Gang (a town site) in central Taiwan during the rice straw burning and non-burning periods. The concentrations of total PAHs accounting for a roughly 58% (34%) increment in the concentrations of total PAHs due to rice-straw burning. Combustion-related PAHs during burning periods were 1.54-2.57 times higher than those during non-burning periods. The mass median diameter (MMD) of 0.88-1.21 microm in the particulate phase suggested that rice-straw burning generated the increase in coarse particle number. Chemical mass balance (CMB) receptor model analyses showed that the primary pollution sources at the two sites were similar. However, rice-straw burning emission was specifically identified as a significant source of PAH during burning periods at the two sites. Open burning of rice straws was estimated to contribute approximately 6.3%-24.6% to total atmospheric PAHs at the two sites.

Comparative health risk of inhaled exposure to organic solvents, toxic metals, and hexavalent chromium from the use of spray paints in Taiwan.

The study investigated the exposure of spray painters to organic solvents, toxic metals, and hexavalent chromium over 21 working days in 2017. The results found these concentrations of 12 VOCs to be below the short-term exposure limit (STEL) established by the US Occupational Safety and Health Administration (OSHA). The mass concentration of total particulate matter (PM) exposure to workers was 20.01 ± 10.78 mg/m3, which exceeds OSHA's permissible exposure level of 15 mg/m3. The mean concentration of the total metals for all particle sizes was 109.1 ± 12.0 µg/m3, and those for lead (496,017.0 ng/m3) and iron (252,123.8 ng/m3) were the highest of metal elements. Significantly, the mean concentrations of Pb and As exceeded OSHA's permissible exposure limits (PELs) of 0.05 and 0.01 mg/m3, respectively. The total hexavalent chromium concentration was 1163.01 ng/m3, and the individual particle sizes (PM1-2.5, PM1, and PM0.25) were strongly and positively correlated with the Cr(VI) concentrations for PM2.5. The study determined that approximately 56.14% of the hexavalent chromium inhaled during the spray-painting process was deposited in the upper respiratory system of the head airway region, followed by the alveolar and tracheobronchial regions, with fractions of 11.93 and 0.05%, respectively. Although the mean ratio of hexavalent chromium to total chromium was only 3.6% for all particle sizes, the cancer risk of the total particles in Cr(VI) (1.6 × 10-3) exceeded the acceptable risk value (10-6). The cancer risks of As and Cr(VI) associated with quasi-ultrafine particles, PM0.5-1, PM1-2.5, and PM> 2.5, also exceeded 10-6. Comparison of the carcinogenicity risk of VOCs and metals suggests that the adverse health effect of inhaled particles on spray-painting workers is more serious than that from VOC exposure.

Effects of open burning of rice straw on concentrations of atmospheric polycyclic aromatic hydrocarbons in central Taiwan.

The sizes and concentrations of 21 atmospheric polycyclic aromatic hydrocarbons (PAHs) were measured at Jhu-Shan (a rural site) and Sin-Gang (a town site) in central Taiwan in October and December 2005. Air samples were collected using semi-volatile sampling trains (PS-1 sampler) over 16 days for rice-straw burning and nonburning periods. These samples were then analyzed using a gas chromatograph with a flame-ionization detector (GC/FID). Particle-size distributions in the particulate phase show a bimode, peaking at 0.32-0.56 microm and 3.2-5.6 microm at the two sites during the nonburning period. During the burning period, peaks also appeared at 0.32-0.56 microm and 3.2-5.6 microm at Jhu-Shan, with the accumulation mode (particle size between 0.1 and 3.2 microm) accounting for approximately 74.1% of total particle mass. The peaks at 0.18-0.32 microm and 1.8-3.2 microm at Shin-Gang had an accumulation mode accounting for approximately 70.1% of total particle mass. The mass median diameter (MMD) of 3.99-4.35 microm in the particulate phase suggested that rice-straw burning generated increased numbers of coarse particles. The concentrations of total PAHs (sum of 21 gases + particles) at the Jhu-Shan site (Sin-Gang site) were 522.9 +/- 111.4 ng/ml (572.0 +/- 91.0 ng/ml) and 330.1 +/- 17.0 ng/ml (or 427.5 +/- 108.0 ng/ml) during burning and nonburning periods, respectively, accounting for a roughly 58% (or 34%) increase in the concentrations of total PAHs due to rice-straw burning. On average, low-weight PAHs (about 87.0%) represent the largest proportion of total PAHs, followed by medium-weight PAHs (7.1%), and high-weight PAHs (5.9%). Combustion-related PAHs during burning periods were 1.54-2.57 times higher than those during nonburning periods. The results of principal component analysis (PCA)/absolute principal component scores (APCS) suggest that the primary pollution sources at the two sites are similar and include vehicle exhaust, coal/wood combustion, incense burning, and incineration emissions. Open burning of rice straw was estimated to contribute approximately 5.0-33.5% to the total atmospheric PAHs at the two sites.

Effects of heavy metals on health risk and characteristic in surrounding atmosphere of tire manufacturing plant, Taiwan.

The health and environmental effects of metal-containing carbon black (CB) particles emitted from a CB feeding area near a tire manufacturing plant were investigated. The mass ratios of PM1 and PM0.1 (UFPs) relative to TSP were 13.84% ± 4.88% and 50.84% ± 4.29%, respectively. The most abundant elements in all fractions were Fe, Al, and Zn. The mean percentage contributions of Al, Fe, Zn, Cu, and Co to the coarse particles ranged from 49.1% to 69.1%, thus indicating that the Al, Fe, and Zn contents in the CB particles were affected by workplace emissions. The ratios of the total mean deposition fluxes of atmospheric particle-bound heavy metals in the human respiratory tracts of workers/adults, workers/children, and adults/children were approximately 5.5, 11.0, and 2.0, respectively. The integrated risks of five elements via two exposure pathways to adults and children were 1.1 × 10-4 and 1.7 × 10-5, respectively; these numbers reflect the high cumulative carcinogenic risk posed by these toxic metals to local residents (both adults and children; limit, 10-6). These results demonstrate the potential health risk presented by particle-bound heavy metals to humans residing near tire manufacturing plants via inhalation and dermal contact exposure.

Industrial PM2.5 cause pulmonary adverse effect through RhoA/ROCK pathway.

According to the Chinese Ministry of Health, industrial pollution-induced health impacts have been the leading cause of death in China. While industrial fine particulate matter (PM2.5) is associated with adverse health effects, the major action mechanisms of different compositions of PM2.5 are currently unclear. In this study, we treated normal human lung epithelial BEAS-2B cells with industrial organic and water-soluble PM2.5 extracts under daily alveolar deposition dose to elucidate the molecular mechanisms underlying adverse pulmonary effects induced by PM2.5, including oxidative damage, inflammatory response, lung epithelial barrier dysfunction, and the recruitment of macrophages. We found that water-soluble PM2.5 extracts caused more severe cytotoxic effects on BEAS-2B cells compared with that of organic extracts. Both organic and water-soluble PM2.5 extracts induced activation of the RhoA/ROCK pathway. Inflammatory response, epithelial barrier dysfunction, and the activation of NF-кB caused by both PM2.5 extracts were attenuated by ROCK inhibitor Y-27632. This indicated that both PM2.5 extracts could cause damage to epithelial cells through RhoA/ROCK-dependent NF-кB activation. Furthermore, the upregulation of macrophage adhesion induced by both PM2.5 extracts was also attenuated by Y-27632 in a co-culture model of macrophages and the epithelial cells. Therefore, our results support that industrial PM2.5 extracts-induced activation of the RhoA/ROCK-dependent NF-кB pathway induces pulmonary adverse effect. Thus, pharmacological inhibition of ROCK activation might have therapeutic potential in preventing lung disease associated with PM2.5.

Carbon black aggregates cause endothelial dysfunction by activating ROCK.

Carbon black nanoparticles (CBNs) have been associated with the progression of atherosclerosis. CBNs normally enter the bloodstream and crosslink together to form agglomerates. However, most studies have used nano-sized CB particles to clarify the involvement of CBN exposure in CBN-induced endothelial dysfunction. Herein, we studied endothelial toxicity of CBN aggregates (CBA) to human EA.hy926 vascular cells. Cell viability, lactate dehydrogenase leakage, and oxidative stress were affected by the highest concentration of CBA. Moreover, transmission electron microscopic results showed that CBA entered cells through membrane enclosed vesicles. Rho-associated kinase (ROCK) is involved in regulating vascular diseases. Thus, we co-treated with the of ROCK inhibitor Y-27632 to study whether other adverse effects caused by CBA are related to activating ROCK. As expected, co-treatment with Y-27632 attenuated CBA-induced cytoskeletal damage, dysfunction of the endothelial barrier, and expression of inflammatory factors. Taken together, these results demonstrate that aggregated CBNs can cause endothelial dysfunction possibly by activating ROCK.

Characteristics of particle-bound polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in atmosphere used in carbon black feeding process at a tire manufacturing plant.

Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were estimated for different particle size distributions in a carbon black feeding process at a tire manufacturing plant on 15 days in March and April of 2014. A total of 75 integrated air samples were collected using a micro-orifice uniform deposition impactor (MOUDI). Particle-bound PCDD/Fs were analyzed using a high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). Concentrations of thoracic particles and total particles produced in the carbon black feeding process of a tire manufacturing plant were measured in ranges of 0.19-2.61 and 0.28-4.22 mg/m(3), respectively. On all sampling days, the three most abundant species of PCDD/Fs were OCDD, 1,2,3,4,6,7,8-HpCDF, and OCDF. The mean concentrations of total PCDD/Fs were 0.74-6.83 pg/m(3) within five particle size ranges. Total I-TEQ in particulate matter (PM)<1.0 was 2.2 and 3.2 times higher than those in PM>18 and PM2.5-10, respectively. However, the total I-TEQ of thoracic PM contributed approximately 74 % of the total I-TEQ of total PM. The assessment of health risk indicates that exposure to fractions of thoracic PM by inhalation poses a significant cancer risk (>10(-6)).

Characteristics of nano-/ultrafine particle-bound PAHs in ambient air at an international airport.

Concentrations of 22 polycyclic aromatic hydrocarbons (PAHs) were estimated for individual particle-size distributions at the airport apron of the Taipei International Airport, Taiwan, on 48 days in July, September, October, and December of 2011. In total, 672 integrated air samples were collected using a micro-orifice uniform deposition impactor (MOUDI) and a nano-MOUDI. Particle-bound PAHs (P-PAHs) were analyzed by gas chromatography with mass selective detector (GC/MSD). The five most abundant species of P-PAHs on all sampling days were naphthalene (NaP), phenanthrene (PA), fluoranthene (FL), acenaphthene (AcP), and pyrene (Pyr). Total P-PAHs concentrations were 152.21, 184.83, and 188.94 ng/m(3) in summer, autumn, and winter, respectively. On average, the most abundant fractions of benzo[a]pyrene equivalent concentration (BaPeq) in different molecular weights were high-weight PAHs (79.29 %), followed by medium-weight PAHs (11.57 %) and low-weight PAHs (9.14 %). The mean BaPeq concentrations were 1.25 and 0.94 (ng/m(3)) in ultrafine particles (<0.1 µm) and nano-particles (<0.032 µm), respectively. The percentages of total BaPeq in nano- and ultrafine particulate size ranges were 52.4 % and 70.15 %, respectively.

The effectiveness of physical leisure time activities on glycaemic control in adult patients with diabetes type 2: A Systematic Review.

REVIEW QUESTION/OBJECTIVE: The objective of this systematic review is to synthesise the best available evidence on the effectiveness of physical leisure time activities on glycaemic control in adult patients with diabetes type 2.The specific review question is:What is the effectiveness of physical leisure time activities on glycaemic control in patients with diabetes type 2? BACKGROUND: Type 2 diabetes results from the body's ineffective use of insulin. Diabetes is a group of diseases marked by high levels of blood glucose resulting from defects in insulin production, insulin action, or both.Type 2 diabetes was previously called non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes. According to 2011 National Diabetes Fact Sheet, diabetes affected 25.8 million people of all ages of United States population during 2005-2008, include 18.8 million diagnosed people and seven million undiagnosed people. Among United States residents ages 65 years and older, 10.9 million, or 26.9 percent, had diabetes in 2010. Recent World Health Organization (WHO) calculations indicate diabetes kills more than one million people annually, almost 80% of which occur in low- and middle-income countries. Almost half of diabetes deaths occur in people aged under 70 years; 55% of diabetes deaths are in women. WHO projects that diabetes deaths will double between 2005 and 2030.Type 2 diabetes is associated with older age, obesity, family history of diabetes, history of gestational diabetes, impaired glucose metabolism, physical inactivity, and race. It is a common outcome of uncontrolled blood sugar and over time leads to serious complications including hypertension, blindness, kidney damage, lower-limb amputations, heart disease, and stroke. Good glycaemic control is a major goal in the treatment of type 2 diabetes mellitus to prevent and delay those severe long-term complications. Physical activity is considered to be a substantial part of the treatment of type 2 diabetes mellitus, as well as diet and medication. Physical activity is a common physiological stressor that causes perturbation to glucose homeostasis and energy needs.Several studies have reported the effects of physical activity on improving insulin sensitivity, cardio-respiratory fitness, glycaemic control, and psychosocial well-being. The American Diabetes Association suggests that people with type 2 diabetes spend at least 150 minutes a week on moderate-intensity physical activity (50-70% of maximum heart rate), or at least 90 minutes a week on vigorous physical activity (>70% of maximum heart rate). Recent studies also indicate that moderate-intensity aerobic physical activity could help type 2 diabetes patients to maintain ideal glycaemic control. Boule et al found physical activity training could reduce haemoglobin A1c (HbA1c) (control group vs. exercise group: 8.31% vs. 7.65%) by 0.66%. This is close to the effect of intense glucose-lowering pharmacological treatment found in the United Kingdom Prospective Diabetes Study. A 1% absolute decrease in the HbA1c value is associated with a 15% to 20% decrease in major cardiovascular events and a 37% reduction in microvascular complications.According to Zhao, Ford, Chaoyang's report (2011), only 25-42% of older adults with diabetes mellitus met recommendations for total physical activity based on the 2007 American Diabetes Association and 2008 Department of Health and Human Services guidelines. Various barriers to regular physical activity had been described, such as health problems, lack of time or energy, no exercise partner, lack of family support, and motivation and working time. An active lifestyle does not require complex exercise programmes. Instead, regular daily physical activity is believed to enable individuals to reduce the risk of chronic diseases and may enhance their quality of life. Recently, it has been thought that, instead of structured physical activity, lifestyle physical activity is a better alternative for diabetes patients. Moderate or vigorous lifestyle or leisure time physical activities included jogging, walking, gardening, tai chi chuan, and qigong (an ancient Chinese breathing exercise that combines aerobics, isometric and isotonic movements and meditation). According to data from recent studies, moderate physical leisure time activities for at least 60 minutes every week can effectively improve glycaemic control in patients with diabetes type 2.Those measure indicators of glycaemic control including glycated hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and postprandial plasma glucose (PPG) were used to assess glycaemic control in diabetic patients. HbA1c value reflects the mean plasma glucose concentration over two to three months. Fasting plasma glucose (FPG) and postprandial plasma glucose (PPG) reflect short-term plasma glucose change. Glycated haemoglobin is a form ofhaemoglobin that is measured primarily to identify the averageplasmaglucoseconcentration over prolonged periods of time. The fasting plasma glucose test measures fasting blood sugar levels and the postprandial plasma glucose test is often used to test the effectiveness of the body's carbohydrate metabolism and the ability to produce insulin. In 2010, Psaltopoulou et al gathered current information from meta-analyses on dietary and lifestyle practices concerning reduction of risk to develop type 2 diabetes. In 2009, Thomas et al completed a systematic review in which fourteen randomised controlled trials involving a total of 377 participants comparing exercise against no exercise in type 2 diabetes were identified. Trials ranged from eight weeks to twelve months duration. Compared with the control, the exercise intervention significantly improved glycaemic control as indicated by a decrease in glycated haemoglobin levels of 0.6%. This systematic review will differ from these two previously published reviews in that it aims to explore the effectiveness of different kinds of moderate or vigorous physical leisure time activities in improving glycaemic control in patients with diabetes type 2. A search of MEDLINE, DARE database, CINAHL, the Cochrane Library of Systematic Reviews and Joanna Briggs Institute Library of Systematic Reviews found no existing reviews or review underway on this topic.