There are very high levels of VOC due to the lush abundance of vegetative matter, but there is no air pollution. Because there is no large manmade industrial NO2 source. About particulates . Trees are sometimes blamed for contrributing to air pollution because of pollen. Considering all the types of particulates, pollen is not a significant contributor to the more serious ill health effects caused by particulates.
Pollen is a relatively large particulate that is readily filtered from the body by the nose.
Health concerns are caused by the presence of smaller particulates from manmade sources that cannot be filtered and therefore enter out lungs. Trees help curb air pollution Through the photosynthesis process, trees take in carbon monoxides emitted by cars and convert this pollutant into oxygen. Thus, trees help clean the air. The complex chemical reactions in our atmosphere that create ozone occur more rapidly with higher temperatures. This is why most Houston ozone noncompliance days occur during the summer.