DBPapers
DOI: 10.5593/sgem2017/52/S20.058

HEALTH RISK TO WASTEWATER TREATMENT PLANT AND AGRICULTURAL WORKERS FROM PATHOGENIC FUNGI IN SEWAGE SLUDGE APPLIED TO LAND

G. Plaza, K. Ulfig
Wednesday 13 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-09-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 52, 449-456 pp, DOI: 10.5593/sgem2017/52/S20.058

ABSTRACT

Many fungi, including keratinolytic species, occurring in sewage sludge and sludge-amended soils possess potential pathogenic properties to humans and animals. For this reason, apart from bacteria, zooparasites and viruses, these fungi pose health risk to wastewater treatment plant and agriculture workers. Assessment of this risk was the aim of the present study. The sludge and sludge-amended soils were provided from one of the Polish wastewater treatment plants. The wastewater treatment technology and the sludge were characterized in previous papers. In this paper, three soil samples, viz. soils after 1 and 10 years after sludge application and control soil (without sludge) were examined for potentially pathogenic fungi. Apart from the dilution pour plating method, the conventional hair baiting method and the hair baiting method combined with dilution and MPN methods were used. The pour plating method provided poor data on pathogenic fungi in sludge-amended soils while with the conventional hair baiting method and the hair baiting method combined with dilution and MPN methods comprehensive results on these fungi were obtained. The qualitative and quantitative composition of pathogenic fungi in the soil after 1 year of sludge application was found to be similar to the sludge fungi composition. In the soil after 10 years after sludge application, the fungi composition lost, to a certain degree, the characters typical for the sludge. The control soil had its own fungal composition. The differences between soils were found to be more quantitative than qualitative in character. Almost all species identified in this study have been recorded as causative agents of mycoses. However, the number of mycotic diseases caused by these fungi has been found to be low and restricted to immunocompromised patients. The mycosis risk to healthy individuals should be assessed low or moderate.

Keywords: sewage sludge, sludge-amended soil, potentially pathogenic fungi, keratinolytic, health risk assessment