TY - JOUR
T1 - Nasal epithelium as a sentinel for airborne environmental pollution
AU - Calderon-Garciduenas, L.
AU - Rodriguez-Alcaraz, A.
AU - Villarreal-Calderon, A.
AU - Lyght, O.
AU - Janszen, D.
AU - Morgan, K. T.
N1 - Funding Information:
We are grateful to all the volunteers that took part in the study. A debt of gratitude is extended to Dr. Alessandra Carnevale, Director of the Instituto Nacional de Pediatria in Mexico City. We extend special thanks to Drs. Hillel S. Koren and Michael C. Madden (U.S. EPA Human Studies Division, Chapel Hill, NC) and Byron Butterworth and Jeffrey Everitt of the Chemical Industry Institute of Toxicology (RTP, NC) for helpful comments and review of the manuscript; Drs. Terry Van Dyke of the Department of Biochemistry and Biophysics and Cindy Lawler of the Brain and Development Research Center (University of North Carolina at Chapel Hill, NC) for advice and encouragement; Donald Joyner for the art work; and Jessica Villarreal-Calderon for the control population clinical assistance. Work was supported in part by NIEHS Training Grant T32 ESO7126.
PY - 1998
Y1 - 1998
N2 - A wide range of chemicals, particulate matter, and gaseous air pollutants are present in urban atmospheres and may pose a significant health risk for human populations. Nasal passages are the first site of contact of the respiratory tract with the environment and offer significant protection to the lower respiratory tract by conditioning the inspired air. This activity, which includes removal of certain pollutants, places the nose at risk of pathological changes, including cancer. Mexico City residents are exposed to a complex mixture of air pollutants. Based on predicted nasal air flow characteristics, four nasal biopsy sites were selected for study in adult male volunteers from a control low polluted town (n = 12) and southwest metropolitan Mexico City permanent residents (n = 54). Clinical data with emphasis on nasal symptoms and histopathological changes including basal and goblet cell hyperplasia, squamous metaplasia, epithelial dysplasia, and neovascularization were evaluated. Immunohistochemical staining was used to assess accumulation of p53 protein. Control individuals had no respiratory symptoms and their biopsies were unremarkable. Mexico City residents complained of epistaxis, rhinorrea, nasal crusting, dryness, and nasal obstruction. Their biopsies showed patchy shortening of cilia, deciliated areas, basal cell hyperplasia, and squamous metaplasia. Dysplastic lesions were predominantly located on antral squamous epithelium and in squamous metaplastic epithelium of the posterior inferior turbinates and they exhibited p53 nuclear accumulation. Individuals with > 10 h of daily outdoor exposure for 5 years or more had the highest rate of dysplasia. Subjects with epistaxis were more likely to have dysplasias and neovascularization. Results of this study suggest: (a) Nasal lesions in Mexico City residents are likely the result of many potentially toxic and/or carcinogenic pollutants, including ozone, aldehydes, particulate matter, and unmeasured pollutants; (b) the alteration of the nasal mucociliary defense mechanisms and the effects of reactive and/or water-soluble materials and particulates could be playing a major role in the nasal pathology; (c) the accumulation of p53 protein in dysplastic nasal lesions in the context of prolonged exposure to air pollutants raises the possibility that p53 mutations are already present and are providing the squamous cells with a selective advantage for clonal expansion; and (d) the nasal passages provide a valuable sentinel tissue for the detection of toxic air pollutants.
AB - A wide range of chemicals, particulate matter, and gaseous air pollutants are present in urban atmospheres and may pose a significant health risk for human populations. Nasal passages are the first site of contact of the respiratory tract with the environment and offer significant protection to the lower respiratory tract by conditioning the inspired air. This activity, which includes removal of certain pollutants, places the nose at risk of pathological changes, including cancer. Mexico City residents are exposed to a complex mixture of air pollutants. Based on predicted nasal air flow characteristics, four nasal biopsy sites were selected for study in adult male volunteers from a control low polluted town (n = 12) and southwest metropolitan Mexico City permanent residents (n = 54). Clinical data with emphasis on nasal symptoms and histopathological changes including basal and goblet cell hyperplasia, squamous metaplasia, epithelial dysplasia, and neovascularization were evaluated. Immunohistochemical staining was used to assess accumulation of p53 protein. Control individuals had no respiratory symptoms and their biopsies were unremarkable. Mexico City residents complained of epistaxis, rhinorrea, nasal crusting, dryness, and nasal obstruction. Their biopsies showed patchy shortening of cilia, deciliated areas, basal cell hyperplasia, and squamous metaplasia. Dysplastic lesions were predominantly located on antral squamous epithelium and in squamous metaplastic epithelium of the posterior inferior turbinates and they exhibited p53 nuclear accumulation. Individuals with > 10 h of daily outdoor exposure for 5 years or more had the highest rate of dysplasia. Subjects with epistaxis were more likely to have dysplasias and neovascularization. Results of this study suggest: (a) Nasal lesions in Mexico City residents are likely the result of many potentially toxic and/or carcinogenic pollutants, including ozone, aldehydes, particulate matter, and unmeasured pollutants; (b) the alteration of the nasal mucociliary defense mechanisms and the effects of reactive and/or water-soluble materials and particulates could be playing a major role in the nasal pathology; (c) the accumulation of p53 protein in dysplastic nasal lesions in the context of prolonged exposure to air pollutants raises the possibility that p53 mutations are already present and are providing the squamous cells with a selective advantage for clonal expansion; and (d) the nasal passages provide a valuable sentinel tissue for the detection of toxic air pollutants.
UR - http://www.scopus.com/inward/record.url?scp=0032434107&partnerID=8YFLogxK
U2 - 10.1006/toxs.1998.2549
DO - 10.1006/toxs.1998.2549
M3 - Article
C2 - 10048139
AN - SCOPUS:0032434107
SN - 1096-6080
VL - 46
SP - 352
EP - 364
JO - Toxicological Sciences
JF - Toxicological Sciences
IS - 2
ER -