Spectormetric Analysis on Spatio–Temporal Bioaccumaltion Anomalies of Air Pollutants in a Bioindicator

The pattern and bioaccumulation of particulate air pollutants on surfaces varies with location and
season. A closer look into these anomalies in the accumulation levels in a well-known versatile
tropical waste land plant, Castor (Ricinus communis) would enable for evaluating its prospective as a
bioindicator of pollution. The spatial differences in pollution accumulation levels across three sites
namely residential, traffic prone and industrially polluted sites were chosen for collection of temporal
effects on bioaccumulation over two seasons namely dry and wet. The X-Ray fluorescence
spectrometric analysis of the levels of accumulated particulate pollutants especially metals and
metallic oxides on the aerial leaves of Castor plant have been confirmed with the Scanning Electron
Microscopic images for the presence of the pollutants. The bioaccumulation anomalies were recorded
for 19 metallic and non metallic particulate matters across 3 sites and 2 seasons. Compared to dry
season, Pb bioaccumulation was high in wet season across all sites. In addition, Pb accumulation was
speculative only in wet season in residential site doubling its level compared to other sites owing to
the increased Pb contamination in underground water from nearby leather industry leachates in rainy
wet seasons. The leaf samples collected from traffic prone sites showed high phytoaccumulation for
Ca and Fe oxides over the wet and dry seasons implying the uniform seasonal and spatial effects of
concrete and metallic body erosions adding upto the air pollution. In case of S, Si and their oxides,
there is a clear seasonal influence as evidenced by high percentages in dry season due to increased
precipitation from air suspensions. A bias for high deposition of S in residential sites than other sites
could be inferred due to agricultural inputs. Whereas, Si accumulation was fluctuating between
Industrial and road sites compared to residential sites. A distinctive anomaly in the phyto
accumulation of Cl was noted across seasons with high levels in wet season in Industrial sites
compared to dry season. But in wet season, Cl accumulation increased in residential sites than
industrial sites implying spatial influence. Where as, the Na anomaly of accumulation was recorded to
vary with space and time with high deposition in road site in dry season and high deposition of its
oxides in industrial site in wet season. Thus this chapter ponders about the variances between time
and space as factors of influence in phyto-accumulation of selected metals, Non metals and their
oxides in Castor plant throwing light in its ability to serve as biondicator of air pollution anomalies.