About the respiratory tract, gasoline can irritate the mucous membranes. But in the case of severe exposures, extensive damage in respiratory tract is possible by gasoline, such as acute exudative tracheobronchitis, edema, intrapulmonary hemorrhage, pulmonary congestion etc. Pneumonitis is possible from the pulmonary aspiration of ingested gasoline. The vapors of petroleum hydrocarbons (e.g. gasoline) can sensitize the myocardium to circulating epinephrine, which may result in the potentially fatal ventricular fibrillation. There is a high possibility for fatty degeneration of the proximal convoluted tubules and glomeruli, and renal failure if massive amounts of petroleum hydrocarbons are inhaled.
Persistent respiratory symptoms with elevated of airway injury in breath condensate has been found in cleanup workers 2 years after Prestige oil spill. But even after 5 years also, Prestige oil spill affected individuals were found to show increased risk of lower-respiratory-track symptoms including cough, phlegm, shortness of breath, wheeze etc., which suggest that the respiratory symptoms may persist up to several years (~ 5 y) after exposure.
In individuals exposed to the Tasman Spirit oil spill have suffered higher rate of health effects such as cough, eye irritation/redness, general illness, head-ache, nausea, runny nose, sore throat etc. But effects were even worse in persons exposed to oil for 15 days at the Tasman Spirit oil spill site, mainly there was lung dysfunctions with significant reductions in the spirometry parameters. On the other hand, several volatile organic compounds (VOCs) such as benzene, ethylbenzene, xylene, and PAHs are known to induce respiratory tract irritation, bronchitis and irritation to skin.
Especially, PAHs with 3 to 5 benzene rings have potential to induce oxidative stress in the respiratory tract and aggravate asthma symptoms.
Multiple diagnostic and clinical tests (e.g. skin prick test, methacholine bronchial provocation test, pulmonary function test) have confirmed that the children exposed to crude oil spill will increase the risk of asthma. VOCs, especially aromatic compounds are associated with adverse respiratory effects like asthma in adults. Nevertheless, respiratory hospitalizations, nocturnal cough, pleural mesothelioma, obstructive lung disease etc., are very common effects in individuals exposed to oil spill. In one study, transcriptomics has been used to reveal the potential effects of oil and oil dispersants on the respiratory system at molecular level. Human airway epithelial cells were grown by exposing them to crude oil, dispersants (Corexit 9500 and Corexit 9527), and oil-dispersant mixtures (Liu et al., 2016).
Corexit 9500 had shown drastic changes in the expression of ~ 84 response genes. According to gene ontology functional term and pathway-based analysis, gene sets related to angiogenesis and immune responses were upregulated, and gene sets involved in cell junctions and steroid synthesis were downregulated. Such effects were observed in cells treated with Corexit 9500, oil or Corexit 9500 + oil mixture. Nevertheless, key molecular signatures identified in this study have been well coincide with pathological features observed in common lung diseases, including asthma, cystic fibrosis, and chronic obstructive pulmonary diseases, which suggest that crude oil and dispersants have an immense effect on respiratory system. Sometimes, as a part of cleanup procedures, spilled sites are treated by “in situ burning” of trapped oil on the surface of water columns. However, this generates potentially toxic substance called oil sail particulate matter (OSPM) (Jaligama et al., 2015).
In experimental mouse, OSPM caused cytotoxicity in a dose- and time-dependent manner, concurrently results in the generation of reactive oxygen species, and superoxide radicles. OSMP exposed mice have shown decreased body weight gain, systemic oxidative stress, airway inflammation. Additionally, OSPM was found to be as a key element in increasing the number of T helper 2 cells (Th2), peribronchiolar inflammation, increased airway mucus production in a mouse model of allergic asthma. These findings clearly demonstrate that OSPM has potential to cause pulmonary inflammation and alters the innate/adaptive immune responses in experimental animals and suggest the threat to respiratory system from cleaning up an oil spill by “in situ burning”. In sub-Saharan Africa, ambient air pollutants have been assessed for their toxicity effects on respiratory system in schoolchildren living in a city (Durban, South Africa) where there is intense activities concerning importation of crude oil and exportation of petroleum and petroleum products (Mentz et al., 2018). As anticipated, increased occurrence of respiratory symptoms among the schoolchildren were identified, with the evidence of chest tightness, cough, shortness of breath etc.