What are the symptoms of excessive formaldehyde inhalation

Formaldehyde is a chemical raw material. Some of the decoration materials we usually use to decorate our homes may contain formaldehyde. There is also a lot of formaldehyde in some chemical plants. If too much formaldehyde is inhaled, it will cause poisoning, which is quite harmful to the human body, especially acute formaldehyde poisoning, which often leads to difficulty breathing, nausea, vomiting, diarrhea and other common symptoms. Chronic formaldehyde poisoning can easily induce tumors and cause blood diseases.

Clinical toxicity symptoms

1. After methanol enters the human body, acute poisoning symptoms will only appear after a latent period of about 18 to 24 hours. The symptoms of acute methanol poisoning have three main characteristics: (1) Central nervous system depression. (2) Severe metabolic acidosis. (3) Changes in the optic nerve.

2. The clinical symptoms of methanol poisoning vary greatly. Generally speaking, the symptoms of poisoning are closely related to the time of seeking medical treatment, but are not necessarily related to the methanol concentration in the blood. The early clinical symptoms of methanol poisoning are mainly caused by methanol itself. The symptoms are similar to those of ethanol poisoning, including rapid heartbeat, abdominal pain, vomiting, diarrhea, loss of appetite, headache, dizziness, general weakness, unsteady gait, and increased deep tendon reflexes; in severe cases, the patient may become confused or have rapid breathing.

3. Late symptoms are mainly attributed to the massive formation of formic acid and the suppression of aerobic breathing, which leads to tissue hypoxia and lactic acidosis. Therefore, they usually occur after 6-12 hours, and may even be delayed until 18-24 hours before obvious symptoms appear. Clinical manifestations may include rapid breathing, increased anion gap, metabolic acidosis, pancreatitis, hyperglycemia, increased osmotic gap, coma, convulsions, bradycardia, left heart failure, shock, elevated white blood cell count, rhabdomyolysis, hypokalemia, hypomagnesemia, acute renal failure (renal tubular necrosis), hematuria, slightly elevated liver function (fatty degeneration), respiratory failure, retinal damage and optic nerve necrosis, etc.

4. Eye damage caused by methanol is the main and special manifestation of methanol poisoning and is of great diagnostic value. The main mechanism of methanol-induced visual impairment is related to formic acid accumulation, which is recoverable if treated early. Symptoms include decreased and blurred vision, constricted visual field, jumping spots of light in front of the eyes, fixed or dilated pupils, congestion of the optic disc, retinal edema and blindness.

5. In addition to the acute symptoms of methanol poisoning, it may also cause permanent neurological sequelae. The probability of developing neurological sequelae is mainly related to the blood pH value and the time of treatment. These include:

(1) Parkinson's disease: It is caused by infarction of the bilateral basal ganglia due to methanol poisoning, and occurs approximately 8 months to 2 years after the poisoning. (2) Limb polyneuropathy, which may be related to brain damage.