Bacteria not fungi drive soil chemical quality index in banana plantations with increasing years of organic fertilizer application.

BACKGROUND: Maintaining or improving soil chemical quality is critical for sustainable agricultural productivity and environmental safeguards. Organic fertilizer application, a common agricultural practice in banana cultivation, is often associated with greater microbial biomass and activity, which are linked to improvements in soil chemical quality. However, the effect of the duration of organic fertilizer application on soil chemical quality and whether it is microbially driven still needs to be investigated. We collected soil samples from banana plantations consistently applying organic fertilizers for 1 (Y1), 4 (Y4), 7 (Y7) and 10 (Y10) years. Soil chemical quality is expressed as total data set (TDS) and minimum data set (MDS) based on chemical indicators, and soil microorganisms are characterized by phospholipid fatty acid (PLFA). RESULTS: Based on TDS and MDS, the soil chemical quality indices in Y7 and Y10 treatments were significantly higher than that in Y1 and Y4 treatments. Soil total PLFA concentrations and the proportional abundance of fungi and arbuscular mycorrhizal fungi increased with prolonged banana cultivation. Total PLFA concentrations were significantly positive correlation with the soil chemical quality index. Soil gram-positive bacteria (G+), bacteria, protozoa and ratio of G+ to gram-negative bacteria (G-) were major drivers of soil chemical quality. CONCLUSION: The organic fertilizer application can significantly improve soil chemical quality, which is regulated by soil bacteria. Regular application of organic fertilizers is important in promoting soil quality and soil biological properties need to be incorporated into the assessment of soil health in banana plantations. © 2022 Society of Chemical Industry.

A cohort study of banana plantation workers in the French West Indies: first mortality analysis (2000-2015).

Chlordecone, an organochlorine insecticide, was widely used in the French West Indies banana plantations. We set up a cohort of banana plantation workers who worked between 1973 and 1993, the period of authorized use of chlordecone. Vital status and causes of death were collected from French national registries. Workers were followed up from 1 January 2000 to 31 December 2015. Cause-specific mortality in the cohort was compared to that of the general population of the French West Indies by computing standardized mortality ratios (SMRs). A total of 11,112 workers (149,526 person-years, 77% men) were included in the mortality analysis, and 3647 deaths occurred over the study period. There was a slight deficit in all-cause mortality, which was statistically significant in men (SMR = 0.93, 95% CI 0.89-0.96), but not in women (SMR = 0.96, 95% CI 0.89-1.04). All-cancer mortality did not differ significantly from that of the general population (men: SMR = 0.96, 95% CI 0.90-1.03; women: SMR = 1.04, 95% CI 0.89-1.21). Significant excesses of deaths were observed for stomach cancer in women (SMR = 1.94, 95% CI 1.24-2.89) and pancreatic cancer in women farm owners (SMR = 2.31, 95% CI 1.06-4.39). Mortality from prostate cancer was similar to that of the general population in the whole cohort (SMR = 1.00; 95% CI 0.89-1.13) and non-significantly elevated among farm workers (SMR = 1.10, 95% CI 0.87-1.36). Non-significant increases in mortality were also observed for lung cancer in women, leukemia in men, and non-Hodgkin lymphoma in both genders.

Micronúcleos y otras anormalidades nucleares en el epitelio oral de mujeres expuestas ocupacionalmente a plaguicidas / Micronuclei and other nuclear abnormalities in the oral epithelium of female workers exposed to pesticides

In order to study if banana fields labour exposure to pesticides produces some kind of DNA damage, we determine the presence of micronuclei in epithelial oral cells in working women in Guapiles and Siquirres, Costa Rica, as an effect biomarker. We also analyzed other abnormalities in the nucleus of those cells such as broken-egg, karyolysis or kariorrhexis, to see if there was some kind of genotoxicity or citotoxicity. The women group exposed to pesticides worked in packing bananas plant from different independent farms. The control group of women had never done any farming tasks; they did not live in the banana fields, neither their husband. We got information about the life style, medical and familial history of the participants through an interview. We did not found any significant increment in the frequency of micronuclei form the exposed group compared with the controls. The other nuclei abnormalities showed signs of citotoxicity or genotoxicity in the controls, associated with the intake of coffee and dental x-rays. These results do not rule out at that pesticides used in packing bananas are agents capable of producing damage to the DNA, but it seems that micronuclei from the oral epithelium is not the most adequate marker to measure it.