Microplastics are a global contaminant with serious consequences for ecosystems and human health, yet their effects on terrestrial soil and plants are poorly understood. We conducted the systematic research to reveal the impact of polyethylene microplastics (PE MPs), polypropylene (PP) MPs and Mixture of PE + PP, size (0.1 – 1 vs 2 – 3.5 mm), concentration (1% vs 5%) on soil biochemical and physiochemical of tomato (Solanum lycopersicum L) health. The results showed that the addition of MPs resulted in elevated soil pH, particularly at 5% concentration and size 2 – 3.5mm. There was a remarkable 30.6 – 47% decreased in soil respiration and inorganic nitrogen levels, after expose to PE, PP, and PE + PP, while plant height, chlorophyll content, and light adapted yield remained unaffected. Microplastics negatively impacted leaf production and fruit production, with 2- 3.5mm MPs sizes leading to 9-20% decreased in leaf number, fruit count and biomass. Additionally, MPs concentration played a role in shoot biomass, with 1% concentrations resulting in 9% reduced biomass. These findings are expected to provide valuable insights into the complex interactions between PE, PP, PP + PE on soil and plant health.


Christopher Ruhland

Committee Member

Mriganka De

Committee Member

Mark Brown

Date of Degree




Document Type



Master of Science (MS)

Program of Study

Environmental Science


Biological Sciences


Science, Engineering and Technology



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