Ecotoxicological assessment of timber-industry wastewater based on bioassays conducted with lettuce seeds (Lactuca sativa L.)

Abstract

The Brazilian timber industry is one of the main activities in the national economy sector due to global increase in reforested wood consumption. Laminated veneer lumber stands out among wood-made products. The production of these materials accounts for generating liquid effluents with highly polluting features; therefore, it is essential acquiring ecotoxicological knowledge, which can be assessed through bioassays conducted with Lactuca sativa L seeds, which is the aim of the present study. Seed germination remained normal up to 75% effluent concentration. Approximately 20% of seeds presented inhibited germination under this condition. However, when 100% of effluent was used in the sample, 40% of seeds had their germination inhibited, likely due to chemical compounds, such as phenol, among other inorganic compounds. Seedling radicle recorded significant growth as effluent concentrations increased. Therefore, toxicological bioassays conducted with L. sativa seeds have proved to be effective in providing knowledge about potential environmental impacts in a simple, reliable and cost-effective manner.