Thanks for your question on Health Care Magic.
I can understand your concern.
No need to worry much for this.
You have Inhaled duster powder and this can actually cause irritation and inflammation of airways.
Some degree of coughing and
Chest pain are common after this kind of inhalation. But if you develop
shortness of breath, wheezing, expectoration,
hemoptysis (blood in sputum) then immediately tell your parents and
consult pulmonologist and start treatment.
Just for
mild cough and chest pain, no need to worry. They will heal by themselves in 1-2 days.
Inhale fresh air, drink plenty of fluids orally and keep yourself hydrated. Don't worry, you will mostly improve in 1-2 days.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.