African Journal of
Environmental Science and Technology

  • Abbreviation: Afr. J. Environ. Sci. Technol.
  • Language: English
  • ISSN: 1996-0786
  • DOI: 10.5897/AJEST
  • Start Year: 2007
  • Published Articles: 963

Full Length Research Paper

Active and passive air quality bio-monitoring in the tropics: Intra-urban and seasonal variation in atmospheric particles estimated by leaf saturated isothermal remanent magnetisation of Ficus benjamina L (Moraceae)

N'guessan Achille Koffi
  • N'guessan Achille Koffi
  • Université Jean Lorougnon Guédé, Unité de Formation Agroforesterie, BP 150 Daloa, Côte d'Ivoire.
  • Google Scholar
Kobenan Pierre N'Gouran
  • Kobenan Pierre N'Gouran
  • Université Jean Lorougnon Guédé, Unité de Formation et de Recherche en Environnement, BP 150 Daloa, Côte d'Ivoire.
  • Google Scholar
Yao Sadaiou Sabas Barima
  • Yao Sadaiou Sabas Barima
  • Université Jean Lorougnon Guédé, Unité de Formation et de Recherche en Environnement, BP 150 Daloa, Côte d'Ivoire.
  • Google Scholar
Djédoux Maxime Angaman
  • Djédoux Maxime Angaman
  • Université Jean Lorougnon Guédé, Unité de Formation Agroforesterie, BP 150 Daloa, Côte d'Ivoire.
  • Google Scholar


  •  Received: 07 October 2019
  •  Accepted: 18 November 2019
  •  Published: 31 December 2019

Abstract

Atmospheric pollutant emissions are likely to increase continously in developing cities like Abidjan (Ivory Coast) where air quality strategies are ineffective or not yet implemented. This could result in a big risk to human health. Local meteorological parameters can have both positive or negative effect on habitat quality depending on the biomonitoring approach used. This study investigates the sources and factors affecting the spatio-temporal variation in particulate pollution in a tropical area in Abidjan (Ivory Coast) using a passive and active biomonitoring approach. Leaf saturated isothermal remanent magnetisation (SIRM) of Ficus benjamina L. was monitored for 2-6 months over 2 consecutive years in four distinct urban land use classes (main roads, industrial zones, residential zones and parks) based on several meteorological parameters (wind speed, temperature, relative humidity and precipitation) and season. Results showed leaf SIRM varied among land use classes and season with main roads and industrial zones presenting higher leaf SIRM during the dry season. This suggests that vehicular exhaust emissions and industrial smokestacks were the main sources of particulate matter (PM) pollution in Abidjan. These results show also the contribution of natural particles from harmattan dust during the dry season. Leaf SIRM was negatively correlated with precipitation intensity, suggesting a wash-off effect of particles on leaves. Results, however, differed between the dry and wet season. During the dry season, leaf SIRM of young leaves was higher than that of old leaves. This trend was reversed during the raining season. This suggests combined effects of meteorology and plant growth/physiology.

 

Key words: Air pollution, saturated isothermal remnant magnetism, particulate matter, ficus benjamina, tropical humid area.