KARACHI, Feb 26: A study on airborne pollen conducted by the Karachi University’s botany department has identified 12 plant species that cause allergies.

The pollen frequency was reported highest in April and September while Conocarpus (buttonwood) — besides grass pollen — species were found to be one of the causative agents of asthma.

Researched by Dr Anjum Perveen, Dr Mohammad Qaiser and Mian Saadul Islam of KU, along with Dr Asif Imam of the Aga Khan University and Hospital (AKUH), ‘Airborne Pollen Survey of Karachi and Adjacent Areas in Relation to Allergy,’ is the first such study in Karachi.

A similar project has also been initiated for entire Sindh.

Giving the details of the study, Dr Perveen said that a total of 14,332 pollen grains per cubic metre were trapped during the four-year project through special equipment to identify and study the qualitative and quantitative properties of pollen, with the help of light and a scanning microscope. The Burkand Spore Trapper was placed at KU, in Malir and near the Super Highway while 44 patients with allergic respiratory disease underwent allergy skin tests at the AKUH’s allergy clinic.

“Out of 32 plant species identified in the study, 11 were confirmed to cause skin reactivity and probable clinical disease. The remaining airborne pollen identified in Karachi could not be related to causing clinical disease because the specific antigens for skin testing were not available here,” she said, recommending the local production of these antigens so that a comprehensive study could be carried out.

She said the concentration of pollen in the atmosphere was also influenced by climatic factors, temperature and humidity.

“Days with high humidity, low precipitation and low temperature show less pollen concentration in the air. However, all windborne pollen didn’t cause allergy; only that which had glycoprotein (a molecule that consists of a carbohydrate plus a protein),” she added.

The allergy causing pollen species were identified as Amaranthus viridus (jungli cholai), Atriplex stocksii, Salsola imbricata (lana), Conocarpus (buttonwood), Cynodon dactylon (lawn grass), Sorghum helepense (baru), Secale cereale (rye), Prosopsis juliflora (kekar), Plantago ovata (ispaghol), Chenopodium album (bathwa), Eucalyptus sp. (sufaida) and Acacia nilotica (babul).

About the significance of the research, Dr Qaiser said: “Earlier, there was no data available on airborne pollen and spores in Karachi in relation to allergic patients. The findings of the study can be translated into a bigger achievement if the private and public sectors take an initiative and invest in manufacturing indigenous drugs for treatment of various pollen allergies.”

Dr Asif Imam, who collaborated in the project for research on pollen-allergy correlation, said that all vaccines for pollen allergies were imported, and therefore treatment costs were high. Also, he said that the study could be helpful in the city’s planning.

“Since some allergy-causing plant species have been identified, the government can take help from the data and avoid planting such species in and around the city,” he said, adding that the incidence of pollen allergy in Karachi was low while house dust, mite and cockroach allergies were more common. Children under 12 were more susceptible.

About future plans, Dr Perveen said the department is still working on pollen flora of Pakistan, a project started 10 years ago, under which 114 families represented by 2,500 species have been studied. The research would help in many other scientific studies including archaeology, forensic and paleoclimatological investigations and oil exploration.

Plans are also in the offing to set up a lab for aerobiological and palynological (study of pollen and spores) investigations at KU and initiate a daily pollen forecast. Also, the Palynology and Aerobiology Society of Pakistan had been set up, which would convene its first meeting next month, she said.