Background: The adverse health effects associated with mass burn incineration are of great concern as large population groups and workers may be exposed to derived toxic substances. Objectives: 1) determining some of the immunological, reproductive,and cytogenetic changes among workers exposed to waste incineration emissions at the waste incineration area of the compost fertilizer plant in Zagazig City, 2)determining the blood lead levels of the studied workers, and 3) assessing airborne particulate matter concentrations at the open dump and waste incineration area. Subjects and methods: This comparative cross-sectional study was conducted on 42 waste incineration workers, who were exposed to waste incineration emissions at the compost fertilizer plant in Zagazig City and a non-exposed control group (51 workers
from 2 sweet factories). All workers were subjected to questionnaires, clinical examinations,and laboratory investigations, that included blood lead levels estimation, immunoglobulins estimation, flow cytometric analysis, and conventional cytogenetic  analysis; While, only 12 workers from both groups agreed to perform semen analysis. Also, sampling of respirable airborne particulates, at the open dump and waste incineration area, was done. Results: Significantly higher percent of waste incineration workers had past history of recurrent infections suggesting depressed immune response
compared to the controls. Also, married waste incineration workers had significantly higher complaints from secondary infertility, decreased libido, and congenital anomalies in their children compared to the married controls. mmunoglobulins and flow cytometric results demonstrated a significant increase in both CD8 and CD 25+cells (P<0.05) and a significantdecrease in CD4/CD8 ratio (P<0.05) among waste incineration workers compared to the control group; while there were no significant differences detected regarding immunoglobulins profile, CD3, and CD4. The results of semen analysis illustrated that, waste incineration workers had a significant decrease in the total sperm count and sperm motility and a significant increase in the percentage of abnormal forms of sperms than did the controls. The conventional cytogenetic analysis of this study revealed significantly higher frequency of chromosomal aberrations (dicentric chromosomes and accentric fragment) among waste incineration workers compared to the controls (P<0.001). Moreover, waste incineration workers with chromosomal aberrations had significantly longer duration of employment than
those without chromosomal aberrations (P<0.05); while, smoking had no significant effect on the results of their cytogenetic analysis. Waste incineration workers were found to have significantly higher blood lead levels (11.8 + 3.4 μg/dl) when compared to the controls (7.8 ± 1.85 μg/dl) (P<0.001). Finally, the average concentration
of the respirable particulate matter in the open dump and waste incineration area was 0.47 mg/m3, which exceeds its threshold limit value (TLV). Conclusion and recommendations:unprotected occupational exposure to waste incineration emissions can cause serious immunological, reproductive, and cytogentic changes. So, a well designed control program is recommended, which should include; avoiding open burning of waste products and promote the use of non- incineration treatment technologies,using incinerators equipped with proper emission control system, continuous environmental and biological monitoring for lead, particulate matter, and other hazardous materials, using immune system parameters, semen quality, and chromosomal aberrations as biomarkers of effect in such workers, and using suitable protective
equipment during work.