Occupational Exposure to Bacteria and Molds in a South-Eastern Citrus Farm

Goals and Objectives: The purpose of this study was to assess the molds and bacteria concentration levels in the air during composting activities in south-eastern citrus farm. Theoretical Framework: One of the riskiest fields to be part of in terms of occupational deaths and injuries is the Agricultural sector. Farmers who believe in letting nature take its course in bioactivity, are constantly exposed to a lot of different microorganisms of which some might be associated with occupational diseases like asthma and other respiratory symptoms. Methodology/Data: Biostage impactor was utilized for air sampling which comprises an inlet cone, an impactor stage, and a base that holds an agar plate, where microorganisms are collected. This impactor meets NIOSH requirements and ACGIH recommendations for sampling bioaerosols. A high-flow pump, QuickTake 30, pulls microorganisms in air through the jets. Atmospheric temperature, and relative humidity were measured by an electronic monitor. We collected 24 samples (n = 12 for bacteria and n = 12 for molds) from different citrus farming fields. Tryptic soy agar plates were used for bacteria and malt extract agar plates were used for molds in the Biostage impactor. Bacterial and mold colonies were counted after 72 hrs of incubation at 29±2°C. Colony counts were converted CFU (colony forming units)/m3. Concentration of airborne culturable bacteria ranged from 897 to 56,290 CFU/m3 (Mean ± SD: 16,132 ± 13,835 CFU/m3) and concentration of airborne culturable molds ranged from 2632 to 91377 CFU/m3 (Mean ± SD: 24,589 ± 31,736 CFU/m3) in different areas of the selected citrus farm. Educational/Field Significance: The preliminary data indicated that overall airborne concentrations of molds are greater than airborne bacteria in the selected areas of the farms. Proposed Significance/Outcomes: Because molds are related to respiratory allergies and asthma, these elevated exposure levels could be an occupational hazard for the farmers

Occupational Exposure to Bacteria, Molds and Particulate Matter in Citrus Greenhouses

Background and Objectives: Citrus farming is common in the southeastern part of the US. 70% of our countries citrus fruits are grown in Florida and farmers in Georgia are adopting citrus farming. Citrus trees are grown in climate controlled greenhouses with associated exposure risks of molds, bacteria, and organic dust particles. The objective of this study was to assess the indoor air quality in several citrus greenhouses. Methods: Biostage viable impactor was utilized for air sampling which comprises an inlet cone, an impactor stage, and a base that holds an agar plate, where microorganisms (molds and bacteria) are collected. Airborne particles, including PM0.5 and PM1 (closer to bacterial and fungal cell sizes) were monitored using a 6-channel (0.3, 0.5, 1.0, 2.5, 5.0 and 10 µm) particle counter with graphical interface which can stores up to 5000 sample records on micro SD card. Atmospheric temperature, and relative humidity were measured with the same device. An anemometer measured the wind speed. Results: Preliminary data showed a range of 10(1) to 10(2) CFU/m(3) of culturable bacteria and 10(2) to 10(3) CFU/m(3) of culturable molds. The concentration ranges for 0.5 µm and 1.0 µm articles were 10(4)-10(5) particles/m(3) and 10(4)-10(6) particles/m(3), respectively. PM1 and PM0.5 were found in higher concentrations in green houses with mature crops. Conclusion: Preliminary data indicates that high levels of fine particles were present in greenhouses with low airflow and higher maturity of plants. The concentrations of bacteria and molds were relatively lower compared to other ambient agricultural activities