Toxicity and health effects of vehicle emissions in Shanghai

Abstract

In China, the number of vehicles is increasing rapidly with the continuous development of economy, and vehicle emission pollution in major cities is more serious than ever. In this article, we summarized the results of a series of short-term assays, animal experiments and epidemiology investigations on the genotoxicity, immunotoxicity, respiratory toxicity and health effects of vehicle emissions in Shanghai, including gasoline exhausts (gas condensate and particles), diesel exhaust particles (DEP) and scooter exhaust particles (SEP). The results showed that: (1) Both gases and particulate phases of the exhausts of different kinds of vehicles showed strong mutagenicity in Ames test (TA98 and TA100 strains), rat hepatocyte unscheduled DNA synthesis (UDS) assay, and mouse micronucleus assay, and vehicle emissions could induce the transformation of Syrian hamster embryo (SHE) cells. DEP and SEP could induce the transformation of human diploid cell strain (KMB-13) cells, immunohistochemistry assay showed that c-myc and p21 proteins were highly expressed in the transformed cells. DEP and SEP could also inhibit the gap junctional intercellular communication (GJIC) of BALB/C3T3 cells (2) Vehicle emissions could decrease the number of macrophages in the lung (bronchial alveolar lavage fluid) (BALF) of male SD rats. Vehicle emissions could also increase the proportion of polymorphonuclear leukocytes (PMN), the content of cetyneuraminic acid (NA), the activity of lactate dehydrogenase (LDH), alkali phosphate (AKP), acid phosphate (ACP) in the lung BALF of the animals. (3) In epidemiology investigation, the proportion of those who have respiratory symptoms and chronic obstructive pulmonary diseases (COPD) in the workers who were exposed to DEP ( n=806) were much higher than those of the controls ( n=413). The OR (odd ratio) values of angina, nasal obstruction, phlegm, short of breath and COPD were 2.27, 3.08, 3.00, 3.19 and 2.32, respectively, and the proportion of those who have indisposed sensation of nose or laryngopharynx, cough, phlegm and pharyngitis in the workers who were occupationally exposed to gasoline exhausts ( n=157) were also higher than those of controls ( n=121), the OR values were 2.43, 3.76, 2.58, and 3.70, respectively, and in the 40 gasoline exhausts exposed workers, the frequencies of 6-TG (thioguanine), sister chromatid exchanges (SCEs) and micronuclei in peripheral blood were markedly higher ( P<0.05) than those of controls. The SI (T lymphocytes transformation) activity, total E rosette, E active rosette, content of immunoglobulin A (IgA) and fibrin (FN) of the exposed group were significantly ( P<0.05) decreased compared with those of the control. All the results showed that vehicle emissions could not only induce adverse effects on respiratory and immune system of occupationally exposed people, but also have potential carcinogenicity to human beings.