Pönkä A, Savela M, Virtanen M
Helsinki City Centre of the Environment, Finland.
Arch Environ Health. 1998 Jul-Aug;53(4):281-6. doi: 10.1080/00039899809605709.
In Helsinki, Finland, from 1987 to 1993, the authors studied the associations between daily concentrations of sulphur dioxide, nitrogen dioxide, ozone, total suspended particulates, and particulates with aerodynamic diameters less than 10 microm (PM10), and the daily number of deaths from all causes and from cardiovascular causes. Investigators used Poisson regressions to conduct analyses in two age groups, and they controlled for temperature, relative humidity, day of the week, month, year, long-term trend, holidays, and influenza epidemics. The PM10 levels were associated significantly with all-cause and cardiovascular mortality among persons under the age of 65 y of age. In the less-than-65-y age group, sulfur dioxide and ozone were also associated significantly with cardiovascular mortality. The effect of ozone was independent of the PM10 effect, whereas sulfur dioxide became nonsignificant when modeled with PM10. An increase of 10 microg/m3 in PM10 resulted in increases in total mortality and cardiovascular mortality of 3.5% (95% confidence interval=1.0, 5.8) and 4.1% (95% confidence interval=0.4, 10.3), respectively. A 20 microg/m3 increase in ozone was associated with a 9.9% (95% confidence interval=1.1, 19.5) increase in cardiovascular mortality; however, ozone results were inconsistent. Moreover, in addition to their separate effects, high concentrations of PM10, ozone, and nitrogen dioxide had a further harmful additive effect. Typically, PM10 was a better indicator of particulate pollution than total suspended particulates. The authors' findings suggest that (a) even low levels of particulates are related to an increase in cardiovascular mortality; (b) ozone--even in low concentrations--is associated, independently, with cardiovascular mortality; and (c) PM10, ozone, and nitrogen dioxide--the essential components of summertime pollution--have harmful interactions at high concentrations.
1987年至1993年期间，作者在芬兰赫尔辛基研究了二氧化硫、二氧化氮、臭氧、总悬浮颗粒物以及空气动力学直径小于10微米的颗粒物（PM10）的日浓度与全因死亡和心血管疾病死亡的日死亡人数之间的关联。研究人员使用泊松回归对两个年龄组进行分析，并控制了温度、相对湿度、星期几、月份、年份、长期趋势、节假日和流感流行情况。PM10水平与65岁以下人群的全因死亡率和心血管死亡率显著相关。在65岁以下年龄组中，二氧化硫和臭氧也与心血管死亡率显著相关。臭氧的影响独立于PM10的影响，而当与PM10一起建模时，二氧化硫的影响变得不显著。PM10每增加10微克/立方米，总死亡率和心血管死亡率分别增加3.5%（95%置信区间=1.0，5.8）和4.1%（95%置信区间=0.4，10.3）。臭氧增加20微克/立方米与心血管死亡率增加9.9%（95%置信区间=1.1，19.5）相关；然而，臭氧的结果并不一致。此外，除了各自的影响外，高浓度的PM10、臭氧和二氧化氮还有进一步的有害相加作用。通常，PM10比总悬浮颗粒物是更好的颗粒物污染指标。作者的研究结果表明：（a）即使是低水平的颗粒物也与心血管死亡率的增加有关；（b）臭氧——即使是低浓度——也独立地与心血管死亡率相关；（c）PM10、臭氧和二氧化氮——夏季污染的主要成分——在高浓度时具有有害的相互作用。
