Pesticide Residues in Mother’s Milk - Pesticides: Evaluation of Environmental Pollution - page 552

Among the locations, no significant difference in the concentrations of DDTs was found
between New Delhi (1500 ng/g lipid weight) and Kolkata (1100 ng/g lipid weight), but the
levels of DDTs in Mumbai (450 ng/g lipid weight) were higher than in the Agra region.
Levels of DDTs in the major cities (urban) were higher than those reported in rural areas
near Agra (180 ng/g lipid weight; Kumar et al. 2006b) and Chidambaram (240 ng/g lipid
weight; Subramanian et al. 2007), indicating higher exposures to DDTs in urban areas than
rural areas. This may probably be due to the ongoing usage of DDT for the eradication of
vector-borne diseases, applied largely in urbanized areas (Subramanian et al. 2007). In
addition, differences in the dietary habits between urban and rural people may also be
responsible for the higher concentrations of DDTs in urban areas because the urban resi-
dents are relatively richer and consume more animal products and protein-rich food that
have more of these lipophilic contaminants (Devanathan et al. 2009).
DDT levels were lower than those in the same locations observed previously; indicating
that the concentration of DDTs has been declining in the Indian environment. For example,
DDTs in human breast milk from New Delhi collected in 1989 were 3700 ng/g lipid wt. and
have declined to 1500 ng/g lipid weight; the DDT levels in Mumbai have declined from 8000
ng/g lipid weight in 1984 to 450 ng/g lipid weight; and, in Kolkata, there was a decline from
4800 ng/g lipid weight in 1984 to 1100 ng/g lipid weight (Devanathan et al. 2009). However,
there is an exception: DDT concentrations in Chennai show an increase from 760 ng/g lipid
weight in 1988 to 1200 ng/g lipid weight in 2003 (Subramanian et al. 2007). Past and ongoing
usage of DDT for controlling vector-borne diseases and/or the continuing intake of contami-
nated foods may be a plausible reason for such an increasing trend (Subramanian et al. 2007).
Breast milk samples from Chennai had higher HCH concentrations (4500 mg/g fat
weight; Subramanian et al. 2007) than the samples from Kolkata (670), Delhi (340), Mumbai
(220) (Devanathan et al. 2009), and Agra (127.25) (Kumar et al. 2006b). These values indi-
cate a continued usage of technical HCH mixture in Chennai and possibly in some other
places in India (Subramanian et al. 2007; Devanathan et al. 2009). It seems that this reflects
a huge amount of usage in the past and/or recent illegal use of technical HCH (Tanabe and
Kuinisue 2007; Kumar et al. 2006b).
Further, it could be seen in Table 17.4 that there is a clear temporal increase in the levels
of HCH and DDT compounds in the human milk samples collected from Chennai during
2002-2003 (Subramanian et al. 2007) when compared with the results published by Tanabe
et al. (1990) from the samples collected during 1988. These results reveal that Chennai
mothers have been exposed to higher amounts of HCHs and DDTs all through these years
than the people living in other parts of the state. The levels of both the chemicals drasti-
cally decreased in the breast milk samples from Parangipettai and Chidambaram, indicat-
ing the effective implication of the bans imposed by the Government of India, whereas
the exemptions permitted for the use of these compounds for vector control in Chennai
boosted their levels in mother's milk. Of the four metropolis evaluated, Mumbai seems to
be less contaminated (DDTs: 450 ng/g; HCHs: 220 ng/g) with respect to these two contami-
nants than the other three cities.
Chlordane compounds and HCB were the least prevalent pollutants detected in all the
regions of India (Table 17.4). CHL levels in human milk (ng/g lipid weight) are relatively
similar among the regions, New Delhi (2.6), Mumbai (3.4), and Kolkata (7.3). The levels
were also relatively similar to those in the southern part of India such as Chennai (7.3 ng/g
lipid weight; Subramanian et al. 2007). Similar to CHLs, contamination with HCB was also
usually low and relatively similar among the regions (Chennai, New Delhi, Mumbai, and
Kolkata were 4.2, 3.2, 1.7, and 4.4 ng/g lipid weight, respectively), probably due to its mini-
mal usage in India (Devanathan et al. 2009).