ENT - September 2020 - 514

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Ear, Nose & Throat Journal 99(8)

Figure 1. Medical visits of epistaxis in 2014 to 2017.

less than 2.5 mm in diameter (PM2.5), particulate matter less
than 10 mm in diameter (PM10), sulfur dioxide (SO2), carbon
dioxide (CO2), nitrogen dioxide (NO2), carbon monoxide
(CO), and ozone (O3). The concentrations of PM2.5, PM10,
SO2, NO2 and CO were all 24-hour average, and the concentration of O3 was moving average of 8 hours. The concentration
unit of CO is mg/m3, the concentration unit of other pollutants
is mg/m3.

Statistical Analysis
Comparisons of air pollutants were performed by T tests and
1-way analysis of variance (ANOVA), comparison of rate was
performed by w2 test. Correlation analysis was performed by
Pearson rank correlation analysis. A 2-tailed P < .05 was
considered statistically significant. Statistical analyses were
performed using SPSS for Windows, version 20.0.

Results
Medical Visits of Epistaxis in Children
From 2014 to 2017, there were 27 508 children who were
diagnosed of epistaxis by otolaryngology department, Capital
Institute of Pediatrics affiliated Children's Hospital, among
which 18 268 (66.41%) cases were males and 9240 (33.59%)
cases were females. Annual visits of epistaxis were 4855, 6554,
6558, and 9541 respectively. Analyzed by 1-way ANOVA, the
number of patients diagnosed as epistaxis was the lowest in
2014, no obvious difference in 2015-2016, significantly higher
in 2017 (P < .05). From 2014 to 2017, the annual visits of
epistaxis reached its 2 peaks in May to June, and August to
September, as shown in Figure 1.
The age distribution of children with epistaxis in 2014 to
2017 showed that the incidence of epistaxis in infants under
1 year of age was very low, increased year by year, reached a
peak between the ages of 4 and 5, and then gradually decreased
with age. The average age was 5.5 years of age. In different age
groups, male patients were more than female patients (P < .05),
as shown in Figure 2.

Figure 2. Age and gender distribution of medical visits of children
with epistaxis in 20l4 to 2017.

Air Pollution in Beijing From 2014 to 2017
Among the outdoor ambient air pollutants in Beijing from 2014
to 2017, the major pollutant is CO, with an annual average of
1.17 mg/m3, followed by PM10, with an annual average of
99.98 mg/m 3, O 3 74.79 mg/m3 , PM2.5 73.22 mg/m 3, NO 2
48.63 mg/m3, SO2 12.41 mg/m3, as shown in Table 1.
Generally speaking, PM2.5, PM10, SO2, NO2, and CO
showed an overall decline from 2014 to 2017, especially in
2017, and the pollutants' concentrations were lower in summer
than in the other 3 seasons. In contrast, O3 was significantly
higher in 2016 and 2017 than in the previous 2 years, and
showed an obvious trend of increase in summer, as shown
in Figure 3.

Relationship Between Visits of Epistaxis and Outdoor
Ambient Air Pollutants
We analyzed the number of cases of epistaxis daily and the
outdoor ambient air pollutants from the day of consultation to
the previous 14 days, as shown in Table 2. The results showed
that the incidence of epistaxis in children was associated with
the concentration of all the pollutants detected from the day of
medical visit to the previous 14 days, P < .01, and the absolute
maximum values of r except the column of O3 were all less
than 0.5. That is to say, the incidence of epistaxis in children
was correlated with the pollutants' concentration, but there

ENT - September 2020

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