title: Climate as the most important factor determining anti-fungal biocide performance in paint films.
abstract: The effect of Pigment Volume Content (PVC) on fungal growth on acrylic paint formulations with and without biocide, exposed to weathering in three different climatic regions in Brazil for four years, was studied. Latex paints, with PVC of 30%, 35% and 50%, were applied to autoclaved aerated concrete blocks pre-covered with acrylic sealer and acrylic plaster. They were exposed to equatorial, tropical and temperate climates in north, south-east, and south Brazil. Cladosporium was the most abundant fungal genus detected in the biofilm on the surfaces of all paint formulations at all sites after four years. Heaviest fungal colonization occurred in the tropical south-east and lightest in the temperate south of the country, but more phototrophs, principally cyanobacteria, were detected in the equatorial region. PVC and presence of biocides were shown to be of less importance than environmental conditions (irradiance, humidity and temperature) for biofilm formation and consequent discolouration. These results have important implications for testing of paint formulations.
authors.affiliation: Escola Politécnica da Universidade de São Paulo, Dept. de Engenharia Civil, Av. Prof. Almeida Prado, trav. 2, n.83, Edif. de Eng. Civil, Cid. Universitária, São Paulo SP, CEP 05508-900, Brazil. shirakaw@usp.br
authors.forename: Márcia Aiko
authors.initials: MA
authors.lastname: Shirakawa
authors.forename: Roberta Gonçalves
authors.initials: RG
authors.lastname: Tavares
authors.forename: Christine Claire
authors.initials: CC
authors.lastname: Gaylarde
authors.forename: Maria Elena Santos
authors.initials: ME
authors.lastname: Taqueda
authors.forename: Kai
authors.initials: K
authors.lastname: Loh
authors.forename: Vanderley Moacyr
authors.initials: VM
authors.lastname: John
mesh_terms: D001562:Benzimidazoles / Q000737:chemistry / Q000633:toxicity; D018441:Biofilms / Q000187:drug effects; D002219:Carbamates / Q000737:chemistry / Q000633:toxicity; D002963:Cladosporium / Q000187:drug effects / Q000254:growth & development; D002980:Climate; D004202:Disinfectants / Q000737:chemistry / Q000633:toxicity*; D004784:Environmental Monitoring; D004785:Environmental Pollutants; D005658:Fungi / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D005659:Fungicides, Industrial / Q000737:chemistry / Q000633:toxicity*; D010150:Paint / Q000633:toxicity*; D013844:Thiazoles / Q000737:chemistry / Q000633:toxicity
chemical_list: D001562:Benzimidazoles; D002219:Carbamates; D004202:Disinfectants; D004785:Environmental Pollutants; D005659:Fungicides, Industrial; D013844:Thiazoles; C512915:isothiazolidinone; C006698:carbendazim