MANILA - A medical expert on Tuesday warned against exposure to volcanic ash that could cause several health problems.

Pulmonologist Dr. Glynna Ong-Cabrera said volcanic ash is made up of small particles that contain water vapor and other gasses like carbon dioxide, hydrogen sulfide and sulfur dioxide.

"If you inhale a lot of carbon dioxide it will cause dizziness, headache for some, others lose consciousness," said Cabrera.

Hydrogen sulfide can cause throat irritation while sulfur dioxide's smell can irritate the airways and can cause runny nose, itchy eyes and throat, coughing and shortness of breath.

"You have to have the mask. The recommended mask is the N95. Unfortunately, as of Sunday evening, nagkaubusan na ng N95. Ang naiwan sa atin medical masks or surgical masks," she said.

(There’s not enough supply of N95. What’s left are medical masks or surgical masks.)

Medical masks do not have the same filtering capacity as N95. Experts urged the public to add more layer to the medical mask to somehow still get that filtering effect.

Authorities earlier said those close to the volcano should use N95 masks, while those in Metro Manila, where the ashfall was not as heavy, may use surgical masks.

• DOH: Wearing N95 face masks in Metro Manila unnecessary

"Sabi nga kaniya-kaniyang pagiging resourceful na lang (they say you just have to be resourceful) to help in the filtration of the particles so some will put cloth or facial tissue," she said.

The Department of Health on Tuesday said people could also use diapers and even bras as alternatives to face mask.

• Diapers, bras, panties can serve as improvised face masks: DOH

Aside from respiratory problems, volcanic ash particles can also affect or damage the eyes.

"Lalo na kung naka-contact lens ka puwedeng magasgas mata mo (Especially if you wear contact lenses, it can scratch your eyes) kaya ang (that’s why) it's advisable also to use goggles so that the gas will not damage your eyes," Cabrera said.

In case of ash exposure, wash eyes with water to remove dust. If possible, do not wear contact lenses and avoid rubbing the eyes.

People with sensitive skin may also develop irritation and allergies due to exposure to volcanic ash.

It is best to protect the skin by wearing long sleeves or long pants.

Children, the elderly and people with pre-existing conditions are the most prone because they have low immune system, she said.

"Seek medical attention kasi kapag pre-existing puwedeng lumala, pwede rin yung symptoms ang nagte-trigger (it could worsen to trigger symptoms) sabi nga natin, shortness of breath, cough, wheezing -- you have to seek medical help," she advised.

Long term exposure may trigger respiratory illnesses including asthma attacks as the lungs become more sensitive.

"Nagwo-worsen yung asthma, bronchitis, COPD (Chronic Obstructive Pulmonary Disorder) but also there's the element of diarrhea, kasi kung doon sa area siyempre yung water and pagkain contaminated magkakaroon sila ng diarrhea o gastrointestinal upset," she said.

(Asthma, bronchitis and COPD may worsen. There’s the element of diarrhea because the water and food in the area may be contaminated and they may develop diarrhea or gastrointestinal upset.)

She said there are theories that volcanic ash may lead to a respiratory disease called silicosis, which may manifest as symptoms including shortness of breath, cough and phlegm.

"So far parang wala pa akong na-encounter na ganun due to volcanic eruptions," she said.

(We have not encountered that so far.)

She advised those with pre-existing conditions to use their maintenance medication.

"If you talk about irritation and allergies, hangga't kasi hindi ka nakakaalis sa area na 'yun o hindi mo napo-protect sarili mo magpapatuloy siya," she said.

(While still in the area and you fail to protect yourself, expect allergies and irritations to persist.)

Sodium chloride nasal sprays may help decongest the nose but doctors have to be consulted first when treating allergies, she added.