Human Health Risk Assessment of Heavy Metals from Bhalaswa Landfill, New Delhi, India - Management of Natural Resources in a Changing Environment - page 207

nausea, vomiting and diarrhoea. Diarrhoea may be accompanied by appetite loss
and abdominal cramping, bloating and discomfort. Zinc poisoning may also cause
flu-like symptoms, including fever, headache, dizziness, chills, lethargy, and body
or muscle aches. More severe side effects include convulsions, severely low blood
pressure and loss of consciousness (Fosmire 1990 ).
Exposure Assessment
Exposure assessment involves measuring or estimating the intensity, frequency, and
duration of exposure to heavy metal in leachate from landfill. The evaluation of the
exposure assessment has been based on previous studies and experience. The first
step involved in exposure assessment is to obtain heavy metal concentration in the
leachate. The data was acquired from the report by Bhalaswa Lok Shakti Manch,
wherein random sampling of groundwater from hand pumps and bore wells was
done to analyze the metal concentrations. The metals that were predominantly pres-
ent were lead (Pb) and zinc (Zn) with highest concentration of 0.053 mg/L and
0.516 mg/L respectively. The permissible limits according to WHO guidelines on
safe drinking water are 0.01 mg/L and 15 mg/L for lead and zinc respectively. The
concentration of zinc in the water samples was within the acceptable limits.
However, lead concentrations were higher than the permissible concentration and
hence included in the exposure assessment. The potential pathways by which
humans could be exposed to lead from leachate are shown in Fig. 1 .
The second step was to identify the possible sources of lead which can be lead
batteries, e-waste, construction waste (having lead-based paint) and chemicals for
photograph processing. All these waste materials reach the landfill when they are
dumped as a part of the municipal solid waste.
The next step was to determine exposure rates (magnitude, frequency, duration).
Average Daily Dose (ADD) and Chronic Daily Intake (CDI) have been calculated
using the default exposure parameters.
1. Ingestion of groundwater contaminated by leachate from
2. Ingestion of surface water contaminated by leachate from
3. Ingestion of contaminated soil/ particulates.
4. Consumption of contaminated fish/vegetables.
5. Dermal exposure (Swimming, farming etc.)
Fig. 1 Potential pathways for lead exposure