Black spotting on the lungs is a sign of pathology rather than a benign variant
the verdict
SUPPORTED
the evidence backs this
refutedsupported
the weight of evidence
3 sources for · 0 against
Peer-reviewed literature establishes that black spots on the lungs, often termed pulmonary anthracosis, indicate morphological alterations and disease associations rather than a benign variant.
Background and Aim: Kathmandu is a densely populated metropolitan city in Nepal. In recent years, however, the metropolis has been ranked as one of the most polluted cities worldwide. Both humans and animals are susceptible to various respiratory diseases due to chronic exposure to polluted air. Due to the relative similarities in the anatomical structure and physiological functions of the respiratory system between humans and dogs, polluted environments may lead to respiratory illness in similar ways in both species living in the valley. On the basis of information on the air quality in the valley, this study was conceived to assess pulmonary illness in street dogs to discern the health hazards caused by polluted air. Materials and Methods: A total of 76 dogs with clinical signs of tachypnea, dyspnea, sneezing, coughing, mucopurulent discharge, moderate hyperthermia, and anorexia admitted from July 2020 to November 2020 in Animal Nepal for treatment were included in this study. Among them, 24 animals responded to treatment, and 52 dogs died during their stay in the hospital. The 52 dead animals were necropsied, and the lesions that resembled pulmonary anthracosis were further studied grossly and histologically in a blinded fashion by trained veterinary pathologists. Results: Significant morphological alterations were observed in the lungs and associated lymph nodes of 25 animals, indicating pulmonary anthracosis. Gross morphological changes included multiple black foci with hemorrhage, congestion, nodular, and emphysema on the parietal and visceral surfaces of the lungs. The alveolar septa and visceral pleura exhibited deposition of black particles. Congestion, emphysema, and inflammatory exudates were also detected in the lung tissues and lymph nodes. Conclusion: The clinical, gross, and microscopic findings accurately resembled those of pulmonary anthracosis. This life-threatening condition in stray canines may be caused by a critical level of air pollution from different sources and carbon emissions from vehicles. To protect animals and humans living in the Kathmandu Valley, concerned government and non-government agencies should work toward reducing air pollution levels as soon as possible.
We discuss the translocation of inhaled asbestos fibers based on pulmonary and pleuro-pulmonary interstitial fluid dynamics. Fibers can pass the alveolar barrier and reach the lung interstitium via the paracellular route down a mass water flow due to combined osmotic (active Na+ absorption) and hydraulic (interstitial pressure is subatmospheric) pressure gradient. Fibers can be dragged from the lung interstitium by pulmonary lymph flow (primary translocation) wherefrom they can reach the blood stream and subsequently distribute to the whole body (secondary translocation). Primary translocation across the visceral pleura and towards pulmonary capillaries may also occur if the asbestos-induced lung inflammation increases pulmonary interstitial pressure so as to reverse the trans-mesothelial and trans-endothelial pressure gradients. Secondary translocation to the pleural space may occur via the physiological route of pleural fluid formation across the parietal pleura; fibers accumulation in parietal pleura stomata (black spots) reflects the role of parietal lymphatics in draining pleural fluid. Asbestos fibers are found in all organs of subjects either occupationally exposed or not exposed to asbestos. Fibers concentration correlates with specific conditions of interstitial fluid dynamics, in line with the notion that in all organs microvascular filtration occurs from capillaries to the extravascular spaces. Concentration is high in the kidney (reflecting high perfusion pressure and flow) and in the liver (reflecting high microvascular permeability) while it is relatively low in the brain (due to low permeability of blood-brain barrier). Ultrafine fibers (length < 5 mum, diameter < 0.25 mum) can travel larger distances due to low steric hindrance (in mesothelioma about 90% of fibers are ultrafine). Fibers translocation is a slow process developing over decades of life: it is aided by high biopersistence, by inflammation-induced increase in permeability, by low steric hindrance and by fibers motion pattern at low Reynolds numbers; it is hindered by fibrosis that increases interstitial flow resistances.
To determine pulmonary anthracosis in zoo, wildlife, and companion animals of Jeollabuk-do Province, South Korea. A total of 350 animals of 61 different species, belonging to 3 classes (mammals: n = 38; avian: 21; and reptiles: 2) from different habitats in Jeollabuk-do Province, were examined. Gross lung examination and tissue sampling were done at postmortem, and histopathological analysis was microscopically done on hematoxylin and eosin-stained slides. Macroscopic analysis of anthracotic lung tissue revealed minute (pinpoint size) spots and black pigmentation in a scattered and/or coalescing fashion. The presence of carbon particles was noted in 154 (44%, 154/350) cases. Based on habitation, zoo animals had the highest frequency of anthracosis in the lung (55.2%, 69/125), followed by companion animals (45.2%, 56/124) and wildlife animals (28.7%, 29/101). There was an association between habitation and the presence of anthracosis (P < .05). This study revealed evidence that the presence of anthracosis is associated with the environmental air quality of zoo, wildlife, and companion animals in Jeollabuk-do Province, South Korea. Air pollution may affect the respiratory health of the endangered species at the Jeonju Zoo as well as the human population. Continuous monitoring of particulate matter and establishing policies that control industrialization around the province would enable quick action to curb any potential respiratory health risks to animals kept in the urban cities of the province.
Everything we examined (3)
This check searched the claim as stated. It did not run a separate search for evidence against it.