The toxicity may also result from non-combustible sources such as the one released from anaerobic fermentation of food grains and anaerobic digestion of biodegradable waste.The World Health Organization (WHO) developed a global recommendation limiting exposures to less than 20 parts per billion for chronic exposure and value less 100 ppb for one hour for acute exposure, using nitrogen dioxide as a marker for other pollutants from fuel combustion. There is a significant association between indoor NO2 levels and increased respiratory symptoms such as wheeze, chest tightness and severity of infections among children with asthma. Historically, some cities in the United States including Chicago and Los Angeles have higher levels of nitrogen dioxide than the EPA maximum exposure limits of 100 ppb for a one-hour exposure and less than 53 ppb for chronic exposure. Signs and symptoms
Nitrogen dioxide poisoning is harmful to all forms of life just like chlorine gas poisoning and carbon monoxide poisoning. It is easily absorbed through the lungs and its inhalation can result in heart failure and sometimes death in severe cases. Individuals and races may differ in nitrogen dioxide tolerance level and individual tolerance level for the gas may be altered by several factors, such as metabolic rate, barometric pressure, and hematological disorders but significant exposure may result in fatal conditions that could lead to shorter lifespan due to heart failure. Acute poisoning
Exposure to high level of nitrogen dioxide may lead to inflammation of the mucous membrane and the lower and upper respiratory tracts.
Diagnosis
Simple bedside tests include response (pain intensity and character) to cotton swab, finger pressure, pinprick, cold and warm stimuli, e.g., metal thermo rollers at 20°C and 40°C, as well as mapping of the area of abnormality.Quantitative sensory testing can be used to determine pain thresholds (decreased pain threshold indicates allodynia) and stimulus/response functions (increased pain response indicate hyperalgesia). Dynamic mechanical allodynia can be assessed using a cotton swab or a brush. A pressure algometer and standardized monofilaments or weighted pinprick stimuli are used for assessing pressure and punctate allodynia and hyperalgesia and a thermal tester is used for thermal testing. Treatment
Hyperalgesia is similar to other sorts of pain associated with nerve irritation or damage such as allodynia and neuropathic pain, and consequently may respond to standard treatment for these conditions, using various drugs such as SSRI or tricyclic antidepressants, Nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, gabapentin or pregabalin, NMDA antagonists, or atypical opioids such as tramadol. Where hyperalgesia has been produced by chronic high doses of opioids, reducing the dose may result in improved pain management. However, as with other forms of nerve dysfunction associated pain, treatment of hyperalgesia can be clinically challenging, and finding a suitable drug or drug combination that is effective for a particular patient may require trial and error. The use of a transcutaneous electrical nerve stimulation device has been shown to alleviate hyperalgesia. See also
Allodynia

References


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