ABSTRACT
Objective @#To investigate the effect of exposure to low concentrations of benzene on miR-155 and miR-223 expression in peripheral blood lymphocytes among workers with benzene exposure. @*Methods @#A hundred male employees at a risk of exposure to benzene (the exposed group) were randomly sampled from two small metal products manufacturing enterprises and one medium-sized chemical raw material and chemical products manufacturing enterprise in Ningbo City, Zhejiang Province, and 60 age-matched male employees without benzene exposure were randomly selected as the unexposed group. Age, body mass index ( BMI ), smoking status, alcohol consumption, disease history, medication history and routine blood testing results of subjects were collected using a questionnaire survey. The 8-hour time weighted average concentration ( CTWA ) of benzene was measured in the workplace using thermal desorption gas chromatography, and the urine 8-hydroxy-2' deoxyguanosine ( 8-OHdG ) levels were determined using high-performance liquid-chromatography tandem mass spectrometry (HPLC-MS/MS). The miR-155 and miR-223 expression was quantified in peripheral blood lymphocytes using quantitative fluorescent reverse transcription-polymerase chain reaction assay, and the factors affecting miR-155 and miR-223 expression were identified using multivariable logistic regression analysis. @*Results @#The subjects in the exposed group had a mean age of ( 31.17±7.30 ) years, and were exposed to low concentrations of benzene ( CTWA, 0.05 to 0.30 mg/m3 ) , while the subjects in the unexposed group had a mean age of ( 32.52±6.15 ) years. There were no significant differences between the exposed and unexposed groups in terms of age, BMI, proportion of smokers or proportion of alcohol consumers ( P>0.05 ). There was no significant difference in the median relative miR-155 expression between the exposed and unexposed groups ( 0.953 vs. 1.293, P>0.05 ), and lower median relative miR-223 expression was quantified in the exposed group than in the unexposed group ( 0.540 vs. 1.433, P<0.05 ). Multivariable logistic regression analysis revealed that down-regulation of miR-223 expression correlated with exposure to benzene ( OR=2.719, 95%CI: 1.308-5.651 ). @*Conclusion @#Down-regulation of miR-223 expression may be associated with exposure to low concentrations of benzene.
ABSTRACT
Objective @#To evaluate the excess mortality risk related to heat wave in Ningbo, Zhejiang from 2013 to 2018, so as to provide a basis for formulating coping strategies for heat wave.@*Methods @#The data of daily mortality, meteorological and air quality from May to October in Ningbo from 2013 to 2018 were obtained from Ningbo Center for Disease Control and Prevention, Ningbo Meteorological Bureau and Environmental Monitoring Center of Ningbo, respectively. The generalized linear model ( GLM ) and distributed lag non-linear model ( DLNM ) were used to estimate the associations between heat wave and cause-specific mortality. @*Results @#Among 1 104 days of the study period, 18 heat waves occured and lasted for 132 days, accounting for 11.96%. A total of 102 954 deaths were reported in the same period. The risks of mortality in circulatory system diseases ( RR=1.09, 95%CI: 1.03-1.16 ), respiratory system diseases ( RR=1.14, 95%CI: 1.04-1.25 ), digestive system diseases ( RR=1.38, 95%CI: 1.15-1.65 ), nervous system diseases ( RR=1.32, 95%CI: 1.08-1.61 ), mental disorders ( RR=1.51, 95%CI: 1.12-2.03 ) and accidental injury ( RR=1.18, 95%CI: 1.06-1.32 ) and all causes ( RR=1.10, 95%CI: 1.06-1.14 ) increased at lag 0-1 day of heat wave. The total excess death related to heat wave was 1 218 ( 95%CI: 731-1 705 ) . The excess deaths of circulatory system diseases, respiratory system diseases, accidental injury, digestive system diseases, nervous system diseases, mental disorders, urinary system diseases and endocrine system diseases were 313 ( 95%CI: 104-556 ), 206 ( 95%CI: 59-368 ), 164 ( 95%CI: 55-292 ), 122 ( 95%CI: 48-208 ), 69 ( 95%CI: 17-131 ), 56 ( 95%CI: 13-113 ), 18 ( 95%CI: -15-64 ) and 3 ( 95%CI: -51-72 ). The excess deaths of urinary system and endocrine system diseases was not statistically significant ( P>0.05 ). @*Conclusion @#Heat wave can increase the mortality risk on the day and after a day in Ningbo from 2013 to 2018. Circulatory system diseases, respiratory system diseases and accidental injury rank top three in excess deaths.
ABSTRACT
Objective@#To analyze the epidemiological characteristics of coronavirus disease 2019 （COVID-19） cases reported in Ningbo from January 22 to February 22, 2020, so as to provide guidance for the prevention and control of the COVID-19 epidemic.@*Methods@#The confirmed cases of COVID-19 reported by Ningbo were selected from National Diseases Prevention and Control Information System to analyze the epidemiological characteristics by descriptive epidemiological method, including time, spatial and population distribution, clinical symptoms and exposure history.@*Results@#A total of 157 confirmed cases of COVID-19 were reported and there was no death. The first confirmed case was reported on January 22. On the incidence curve, the peak was from January 22 to February 4, with a maximum of 15 cases in a single day. The incidence curve presented sustained human-to-human transmission. The number of the cases showed a declining trend from February 5. The confirmed cases were reported in all 10 counties（cities or districts）,among which 69（43.95%）cases were reported in Haishu District. The confirmed cases were mainly 30-69 years old,accounting for 78.34%;were mainly farmers,household workers and retired people,accounting for 59.87%;and were mainly clinically mild,accounting for 87.90%.There were 51 imported cases, accounting for 32.48%. The initial confirmed case was a local case. In the early stage of the epidemic, local cases and imported cases prevalent together,which was due to the outbreak caused by the large-scale buddhist activity on January 19.This event resulted in 67 confirmed cases and 15 asymptomatic cases. There totally reported 22 clusters with 138 （87.90%）confirmed cases. @*Conclusions@# In the early stage of the COVID-19 epidemic in Ningbo, the imported cases and local cases prevalent at the same time. Most of the cases were female, aged from 30 to 69 years, and their occupation were farmers, household workers and retired people. With comprehensive measures taken, the epidemic of COVID-19 in Ningbo have been under control.