ABSTRACT
Background Polycyclic aromatic hydrocarbons (PAHs) are one of the most widely distributed and harmful organic pollutants in the atmosphere. Objective To investigate the distribution characteristics and composition sources of PAHs in the atmosphere of two districts of Lanzhou from 2019 to 2020 and evaluate the health risks of PAHs via inhalation to different populations. Methods The PAHs concentrations in two urban areas (Chengguan District and Xigu District) of Lanzhou City from January 2019 to December 2020 were regularly monitored. Mann-Whitney U test was used to compare differences in target pollutant concentrations between the two areas. Diagnostic ratio method and principal component analysis were adopted for source identification. Incremental lifetime cancer risk (ILCR) model was applied to evaluate the health risks of PAHs. Results The M (P25, P75) PAHs concentrations in Chengguan District and Xigu District were 24.04 (14.59, 41.81) ng·m−3 and 25.97 (18.59, 42.56) ng·m−3, respectively, with no significant difference (Z=−0.970, P>0.05). As to seasonal distribution, most PAHs monomer concentrations in Chengguan District were higher than those in Xigu District in summer, and the concentrations of benzo[a]anthracene and benzo[g,h,i]perylene in Chengguan District were also higher than those in Xigu District in spring and autumn (P<0.05), but there were no significant differences in PAHs monomer concentrations between the two urban areas in winter (P>0.05). Ring number of PAHs exhibited seasonal fluctuations. In winter and spring, the highest proportions in Chengguan District and Xigu District were both 4-ring PAHs (37.32%-41.73%, 35.20%-39.66%), and in summer and autumn, the highest proportions were both 2- and 3-ring PAHs (39.38%-49.54%, 47.17%-51.23%). The results of diagnostic ratio method revealed mixed atmospheric PAHs sources in the two urban areas, including fossil fuel, coal, and biomass combustion. The results of principal component analysis showed that the cumulative contribution rate of the four principal component factors reached 79.54%. Principal component 1 included phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene; principal component 2 included acenaphthene and dibenzo[a,h]anthracene; principal component 3 was fluorene; principal component 4 was naphthalene. The results of health risk assessment showed that the ILCR values of adult males, adult females, and children in Chengguan District were 2.30×10−6, 2.16×10−6, and 1.73×10−6, respectively; and those in Xigu District were 1.58×10−6, 1.48×10−6, and 1.19×10−6, respectively; all were greater than 10−6. Conclusion PAHs pollution exists in the atmosphere of the two urban areas of Lanzhou City, mainly comes from mixed sources of fossil fuels, coal, and biomass burning, and may pose potential carcinogenic risks to the population.
ABSTRACT
Background Air pollutants PM2.5 and its adsorbed metal elements are important factors affecting public health. Objective To explore the distribution characteristics and sources of metal elements in atmospheric PM2.5 in Lanzhou from 2019 to 2020, and to assess the health risks of metal elements to different groups of residents through inhalation. Methods From January 2019 to December 2020 in two districts of Lanzhou City (Chengguan District and Xigu District), regular PM2.5 and metal elements [antimony (Sb), aluminum (Al), arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), lead (Pb), manganese (Mn), nickel (Ni), selenium (Se), and thallium (Tl)] were regularly monitored, and their concentrations were described by the median (M) and 25th and 75th percentiles (P25, P75) as not following a normal distribution (because the detection rates of the five elements Be, Cr, Hg, Ni, and Se were less than 70%, the five elements were not included in subsequent analysis), and then compared with the secondary concentration limits in the Ambient Air Quality Standards (GB 3095-2012). The differences between the medians of the two groups were compared by the Mann-Whitney U rank sum test, and the differences among the medians of multiple groups were compared by the Kruskal-Wallis H rank sum test; the enrichment factor (EF) method and principal component analysis were used to evaluate the pollution degree of the metals and their sources; the health risks of five non-carcinogenic metals (Sb, Al, Pb, Mn, and Tl) and two carcinogenic metals (As and Cd) in PM2.5 were evaluated by hazard index (HI) and hazard quotient (HQ) using the incremental lifetime cancer risk (LCR) model and the non-carcinogenic risk assessment model, respectively. Results The PM2.5 concentrations [M (P25, P75)] in Lanzhou City were 38.50 (26.00, 65.00) and 41.00 (29.00, 63.10) μg·m−3 in 2019 and 2020, respectively, and the difference was not statistically significant (Z=−0.989, P > 0.05). The average levels of the metal elements from high to low were: Al > Pb > Mn > As > Cd > Sb > Tl, and the annual average concentration of each metal element in 2019 was higher than that in 2020 (P<0.05). The M ( P25, P75) of PM2.5 concentrations in Chengguan and Xigu districts were 52.98 (17.00, 61.00) and 55.40 (17.00, 67.00) μg·m−3, respectively, with no statistically significant differences (P<0.05); the concentrations of Sb and Al in Chengguan District were lower than those in Xigu District (P<0.05), and the concentrations of other metal elements were not different between the two areas (P>0.05). There were seasonal differences in the concentrations of PM2.5 and seven metal elements in Lanzhou City (except PAl=0.007, the other Ps < 0.001). The results of the enrichment factor method showed that the EF values of the six metals (Sb, Al, As, Cd, Pb and Tl) were all greater than 1. Among them, except As, the EF values of other metal elements were all greater than 10, and the EF values of Al and Cd were both greater than 100. The results of principal component analysis showed that the variance contributions of the three principal components were 45.61%, 24.22%, and 14.42%, and the cumulative contribution reached 84.25%. The principal component 1 included Pb, As, Cd, and Sb, the principal component 2 included Al and Mn, and the principal component 3 contained Tl. The non-carcinogenic risks of the five metals were, in descending order, Al > Mn > Pb > Tl > Sb, among which the HQ values of the remaining four metals were less than 1 for adults and children, except the HQ value of Al for adults, which was greater than 1. The ILC values of carcinogenic metal As for adult males, adult females, and children were 2.68×10−5, 2.51×10−5, and 1.45×10−5, respectively; the ILC values of carcinogenic metal Cd for adult males, adult females, and children were 1.53×10−6, 1.43×10−6, and 8.26×10−7, respectively. Conclusion There is pollution of atmospheric PM2.5 and its adsorbed metal elements in Lanzhou. As and Cd elements may pose potential carcinogenic risks to the residents.
ABSTRACT
Objective@#To understand the pollution characteristics and assess the pollution health risks of heavy metals in atmospheric PM2.5 in Lanzhou.@*Methods@#According to the regional characteristics of air pollution and industrial distribution characteristics in Lanzhou, atmospheric PM2.5 was sampled monthly in Chengguan and Xigu Districts from January, 2015 to December, 2016. Detected the concentration of PM2.5 and 12 kinds of elements (Sb, Al, As, Be, Cd, Cr, Hg, Pb, Mn, Ni, Se and Tl) by weighing method and inductively coupled plasma mass spectrometry. Enrichment factor and geo-accumulation index were used to describe the pollution characteristics, while health risk assessment was conducted using the recommended United States Environmental Protection Agency (USA EPA) model. The health risks of non-carcinogens were evaluated by non-cancer hazard quotient (HQ), the non-carcinogenic risk was considered to be negligible when HQ<1, HQ>1 meant a health risk. With a single contaminant cancer Risk value to evaluate the health risks of carcinogens, when the Risk value between 10-6 to10-4 as an acceptable level.@*Results@#The daily average concentrations of PM2.5 was 83.0 μg/m3, 77.0 μg/m3 in Chengguan and Xigu Districts, respectively, during the sampling periods, and the concentration of PM2.5 in winter/spring was higher than summer/fall in both districts. The concentration of Al in PM2.5 was the highest and other elements in descending order: Pb, Mn, As, Sb/Cd, Tl in both districts. Enrichment factor results showed that Al and Mn were mainly affected by natural factors, the rest of five elements were all typical man-made pollution elements and according to geo-accumulation index pollution level of Cd was the strongest in the winter. The results of health risk assessment showed that Mn had the highest non-cancer risks (HQ>1) and affected the health of the children seriously. HQ reached up to 2.44 and 1.79 in Chengguan and Xigu Districts, respectively. Pb, As, Sb, Cd had slight health impact (HQ<1), could be negligible. The cancer risks range of As, Cr were 6.33×10-6 to 6.46×10-5 between the acceptable level of risk (10-6 to 10-4), which indicated that As and Cd had potential cancer-risks.@*Conclusions@#The pollution level of atmospheric PM2.5 and the heavy metals in it was still grim;the non-cancer risks caused by multiple metals on children deserved attention. Although the cancer risks of As and Cd were between the acceptable level of risk, the potential cancer risk still shall not be ignored.
ABSTRACT
Objective To study the distribution of surfactant protein A2 (SP-A2) haplotype and its association with preterm respiratory distress syndrome (RDS) susceptibility in a local Chinese cohort.Methods Using population base and case-control study cohorts,genotyping for four single nucleotide polymorphism (SNP) was performed,rs1059046,rs17886395,rs1965707,rs1965708,in 80 term infants,50 preterm infants with RDS (RDS group) and 50 preterm infants without RDS(control group) by using TaqMan (R) real-time polymerase chain reaction.Infants in RDS group and control group were matched according to gender and gestational age.Frequency of each haplotype was compared between preterm infants with RDS and without RDS,term infants and preterm infants without RDS.Results Most common haplotypes in term infants were 1A0,1A5,1A1.In each preterm infants groups with RDS and without RDS,1A0,1 A5,1 A1 were also the most common haplotypes.Among these three common haplotypes,frequency of 1A0 was lower in preterm infants,including RDS group and control group,than that in term infants.No significant difference was found between preterm groups with RDS and without RDS (P ＞ 0.05),neither in preterm infants with gestational age ≥32 or ＜ 32 weeks.Haplotype 1A0 frequency(0.542) in term infants was significantly higher than that in preterm infants ＜ 32 weeks without RDS (0.329) (x2 =6.06,P =0.01).Conclusions SP-A2 haplotype distribution in a local Chinese population shows ethnic characteristics to some extent.Only SP-A2 does not contribute to the susceptibility for preterm RDS.
ABSTRACT
Neonatal bacterial meningitis may lead to severe neurological sequelaes,with a high mortality rate.It shows different etiology characteristics in different regions and different days of age.The lack of specific clinical manifestations of the disease,easily lead to delays in diagnosis and treatment.Diagnosis needs to realize cerebrospinal fluid (CSF) culture and biochemical parameters by lumbar puncture,however,the rate of positive in CSF culture is extremely low,and the sensitivity in biochemical parameters in the early days and after treatment with antibiotics may be decreased.The reverse transcription-PCR technique may improve the early diagnosis of specificity and sensitivity,but which is expensive and restricted by technical conditions,therefore,clinicians should be alert to the suspicious children and to check in time even repeated lumbar puncture.The third generation of cephalosporins antibiotics are the choices for gram-negative bacilli,gram-positive coccus preferred vancomycin,hormone application is still not advocate.Because of greater incidence of neurological complications of bacterial meningitis in neonates,head imaging examination timely in treatment process is an important means of assessing prognosis.
ABSTRACT
Objective To explore the conditions, safety and efifcacy of exchange transfusion for extremely severe hyper-bilirubinemia in term newborns requiring mechanical ventilation. Methods Ten full-term newborns of extremely severe hyper-bilirubinemia requiring mechanical ventilation were selected from January 2010 to March 2013 in the department of neonatology. After stable vital sign was achieved by the use of conventional life support, peripheral arterial and venous synchronous exchange transfusion was performed. The bilirubin, platelets, blood calcium, blood coagulation and blood gas were monitored before and after exchange transfusion. The effects and adverse events of exchange transfusion in newborns on mechanical ventilation were observed. Results There was no death in the study, and the replacement rate of total bilirubin was 50.5%. The main adverse event was thrombocytopenia (80%). There was a signiifcant difference in platelet counting before and after exchange transfusion (P<0.05). There was no signiifcant difference in blood coagulation, pH/HCO3-of the blood gas, prothrombin time (PT) and acti-vated partial thromboplastin time (APTT) before and after exchange transfusion. Conclusions It is relatively safe to implement an exchange transfusion in the full-term newborns with severe hyperbilirubinemia in newborns requiring mechanical ventilation, but the use of conventional life support is prerequisite because it stabilizes vital signs. The relatively ideal replacement rate of bili-rubin and the low incidence of adverse reactions are expected. However long-term prognosis of neural system is still unknown.