Scientists can tell if fish have been exposed to this blue dye by checking their blood — changes in red and white blood cells are clear warning signs.
Scientific Claim
Hematological parameters such as hemoglobin levels, total leukocyte count, and red blood cell morphology in Labeo rohita are associated with sub-lethal methylene blue exposure and may serve as reliable indicators of its toxic effects.
Original Statement
“validating hematological biomarkers as reliable indicators of sub-lethal toxicity”
Evidence Quality Assessment
Claim Status
overstated
Study Design Support
Design cannot support claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The term 'validating... reliable indicators' implies confirmation of diagnostic utility, but the study lacks external validation or sensitivity/specificity analysis. Only association is demonstrated.
More Accurate Statement
“Hematological parameters such as hemoglobin levels, total leukocyte count, and red blood cell morphology in Labeo rohita are associated with sub-lethal methylene blue exposure and may serve as potential indicators of its toxic effects.”
Evidence from Studies
Supporting (1)
The study found that even small amounts of methylene blue made fish blood look abnormal, lowered their oxygen-carrying hemoglobin, and changed their white blood cell counts—proving these blood changes can be used to tell if the fish are being harmed by the chemical.