大氣懸浮微粒對血壓和心臟血管功能的影響

隨著快速工業化及都市化，空氣污染已成為台灣近年來重要的公共衛生議題。許多研究已證實大氣中懸浮微粒污染對人體器官的危害，其中尤以心血管系統為甚。本文回顧台灣有關懸浮微粒短期和長期暴露對血壓及心臟血管血流動力學參數變化的研究。動物實驗及流行病學研究結果顯示懸浮微粒短期暴露會造成血壓的浮動變化，然而方向性並不一致。小組研究及實驗型研究結果進一步證實懸浮微粒短期暴露會導致脈搏壓降低、心臟收縮力變差、及血管順應變差或血管阻力增加。懸浮微粒長期暴露則會導致血壓上升及頸動脈內膜厚度增加。此外，懸浮微粒暴露和血壓及血流動力學變化的關係會因個人特質、排放源、或懸浮微粒中的化學成分不同而有不同的效應。綜合以上研究結果證實短期懸浮微粒空氣污染主要是造成心臟或血管的功能失調；而長期懸浮微粒空氣污染則是因血壓上升以及動脈硬化導致心血管系統的危害

Ambient air pollution (AAP) has become an important public health issue in Taiwan following the rapid industrialization, motorization, and urbanization in the past decades. An increasing body of evidence suggest the harmful effects of AAP, especially particulate matter (PM) on human health, among which the impacts of PM on cardiovascular health were most documented. Blood pressure (BP) change cardiovascular dysfunction have been proposed as important biomechanisms linking PM and cardiovascular disease. In Taiwan, several experimental and epidemiological studies observed BP fluctuations were associated with short-term PM exposures to PM, but the results were inconsistent. However, short-term exposures to PM were observed to associate with pulse pressure narrowing, decreases in cardiac contractility and vascular compliance, or increase in vascular resistance both in panel and experimental studies. Using land use regression model, a new-developed technique to estimate individual’s long-term PM exposures, two studies further demonstrated that long-term exposures to PM are associate with increases in diastolic BP and carotid intima media thickness. Also, the cardiovascular metrics in response to PM may differ by individual characters, emission sources, or chemical components. In summary, the impact of short-term exposures to PM on cardiovascular system may be primarily through cardiac and vasomotor dysfunction rather than BP fluctuation; while long-term exposures to PM are associated with elevated BP and atherosclerosis.