Neuberger Manfred, Moshammer Hanns
Abteilung für Präventivmedizin, Institut für Umwelthygiene der Medizinischen Universität Wien, Wien, Osterreich.
Wien Klin Wochenschr. 2004;116 Suppl 1:8-12.
Based on several severe air pollution episodes, a temporal correlation between high concentrations of particulate matter (PM) and SO2 pollution and acute increases in respiratory and cardiopulmonary mortality had been established in Vienna for the 1970's. After air pollution had decreased in Austria in the 1980's--as documented by data on SO2, and total suspended particles (TSP)--no such associations between day-to-day changes of SO2 and TSP and mortality have been documented any more, however, traffic related pollutants like fine particles and NO2 remained a problem. Therefore, short term effects of PM on lung function, morbidity and mortality were investigated in Vienna, Linz, Graz and a rural control area. Long-term exposure and chronic disease--even more important for public health--were studied in repeated cross-sectional, a mixed longitudinal and a birth cohort study on school children in the city of Linz. Lung function growth was found impaired from long-term exposure to air pollutants and improved in districts where ambient air pollution had decreased. Where only TSP and SO2 had decreased, no continuous improvement of small airway function was found and end-expiratory flow rates stayed impaired where NO2-reduction from technical improvements of cars and industry was counterbalanced by increase of motorized (diesel) traffic. Remaining acute effects of ambient air pollution in 2001 from PM, NO2 and co-pollutants found in a time series study also show that continuing efforts are necessary. Active surface of particles inhaled several hours to days before spirometry was found related to short-term reductions in forced vital capacity-FVC (p<0.01), forced expiratory volume in one second-FEV1 (p<0.01) and maximal expiratory flow rate at 50% of vital capacity-MEF50 (p<0.05). In pupils with asthma or previous airway obstruction 4-week-diaries proved that the following symptoms increased with acute exposure to higher active surface of particles: wheezing (p<0.01), dyspnea, cough when going to sleep, cough at night (p<0.05). Efforts to reduce exposure to fine particles from motor traffic and passive smoking have to be increased if we want to achieve full recovery of children from air pollution effects and best respiratory performance in adulthood. Surveillance seems to be necessary not only for particle mass but also for particle number and surface. Little is known on the mechanisms of irreversible long-term effects of PM such as myocardial infarction and cancer. In a prospective cohort study on 1630 dust-exposed and 1630 non dust-exposed workers matched for smoking we found an increase of lung cancer related to nonfibrous insoluble PM. Other studies were able to relate lung cancer to specific particles like those from diesel engines, and a large prospective study of the American Cancer Society was able to link lung cancer in the general population with long-term exposure to fine particles from combustion processes. All these recent epidemiological findings will have consequences for occupational and ambient air PM standards.
基于几次严重的空气污染事件,20世纪70年代在维也纳已确定高浓度颗粒物(PM)和二氧化硫污染与呼吸道及心肺死亡率的急性增加之间存在时间相关性。20世纪80年代奥地利空气污染有所下降(如二氧化硫和总悬浮颗粒物数据所示),然而,此后再未记录到二氧化硫和总悬浮颗粒物的日常变化与死亡率之间存在此类关联,不过,与交通相关的污染物如细颗粒物和二氧化氮仍是问题。因此,在维也纳、林茨、格拉茨及一个农村对照地区对PM对肺功能、发病率和死亡率的短期影响进行了研究。在林茨市针对学童开展的重复横断面研究、混合纵向研究和出生队列研究中,对长期暴露和慢性病(对公众健康更为重要)进行了研究。发现长期暴露于空气污染物会损害肺功能增长,而在环境空气污染有所下降的地区肺功能得到改善。仅总悬浮颗粒物和二氧化硫下降的地方,未发现小气道功能持续改善,在汽车和工业技术改进使二氧化氮减少但被机动化(柴油)交通增加抵消的地方,呼气末流速仍受损。2001年时间序列研究中发现的环境空气污染中PM、二氧化氮和共污染物的剩余急性影响也表明仍需持续努力。在肺活量测定前数小时至数天吸入的颗粒物活性表面与用力肺活量 - FVC(p<0.01)、一秒用力呼气量 - FEV1(p<0.01)和肺活量50%时的最大呼气流量 - MEF50(p<0.05)的短期降低有关。在患有哮喘或既往有气道阻塞的学生中,为期4周的日记证明,以下症状会随着急性暴露于更高活性表面的颗粒物而增加:喘息(p<0.01)、呼吸困难、入睡时咳嗽、夜间咳嗽(p<0.05)。如果我们希望儿童从空气污染影响中完全恢复并在成年后获得最佳呼吸功能,就必须加大力度减少机动车交通和被动吸烟产生的细颗粒物暴露。监测似乎不仅对颗粒物质量有必要,对颗粒物数量和表面也有必要。对于PM的不可逆长期影响(如心肌梗死和癌症)的机制知之甚少。在一项针对1630名接触粉尘和1630名未接触粉尘且吸烟情况匹配的工人的前瞻性队列研究中,我们发现与非纤维性不溶性PM相关的肺癌有所增加。其他研究能够将肺癌与特定颗粒物(如柴油发动机产生的颗粒物)联系起来,美国癌症协会的一项大型前瞻性研究能够将一般人群中的肺癌与长期暴露于燃烧过程产生的细颗粒物联系起来。所有这些最新的流行病学发现将对职业和环境空气PM标准产生影响。