CHARACTERIZATION OF POLYCYCLIC

AROMATIC HYDROCARBONS

IN MOSQUITO COIL EMISSIONS

Presented by :- ANAMIKA BANERJEE

INTRODUCTION

POLYCYCLIC AROMATIC HYDROCARBONS

Include carbon and hydrogen atoms in a fused ring structure containing at least two benzene rings.

Their production is favored by an oxygen deficient flame.

There is an increasing concern about the occurrence of PAHs in the environment because they are identified as carcinogenic and mutagenic compounds.

LIST OF 16 PAHs REGULATED BY EPA

Nap Acy Ace

Flu Phen Anth

Fla Pyr

Chy BaA

BbF BkF

BaP

DbA

IP

Bg,h,iP

SOURCES NATURAL COMBUSTION EMISSIONS

ANTHROPOGENIC EMISSIONS

PHYSICO CHEMICAL PROPERTIES Governed by the size and shape of the individual

molecule.

Molecular weight ranges from 128 – 300g.

Low molecular weight PAHs ,eg:

LOW MOLECULAR WEIGHT

HIGH MOLECULAR WEIGHT

• soluble • volatile

• less hydrophobic

• those with high vapour pressure are

predominant in gaseous phase.

High molecular weight PAHs, eg:

PAHs are highly lipophilic and are stored in fat tissues.

Solubility of PAHs in water is inversely proportional to the number of rings it contains.

They can undergo photo oxidation.

• do not volatilize because they have high melting point.

• found mainly adsorbed on particulate matter

They can be deposited either by direct impact of particles and gaseous molecules on surface (dry deposition) or by precipitation (wet precipitation)

PAH EMISSIONS FROM MOSQUITO COIL

Burning mosquito coil generates smoke that acts as an efficient mosquito repellant.

Smoke of coil contains variety of PAHs and these are mainly dominated by 3 rings or 4 rings PAHS.

When a mosquito coil is burnt the insecticide evaporates and the remaining component of mosquito coil viz., organic fillers, binders, dyes and other additives undergo incomplete combustion.

Smouldering combustion emits 4 -5 times more PAHs than flaming combustion.

Large amount of gaseous pollutants such as

; ;

ACENAPHTHENE PHENANTHRENE BENZO(A)PYRENE

are generated along with sub micrometer particles during the combustion process.

In general, fine particulate PAHs concentrations

are higher than coarse particulate PAHs concentrations in the smoke emissions.

Burning one mosquito coil would release the same amount of PM 2.5 as burning 75 – 137 cigarettes.

HEALTH EFFECTS

PAH concentration is highly dependent upon the size of airborne particulate matter, with the greatest concentration being in the respirable size range.

In CHILDREN, it results

SHORT TERM HEALTH IMPACT

EYE IRRITATION

NAUSEA

CONFUSION

LONG TERM HEALTH IMPACT

According to

MUTAGENIC POTENTIAL

PAH adhere to DNA