Abstract
Open dumping and burning of waste contaminated with mercury are known mercury emission sources in the environment, especially in developing countries. However, little data are available to understand the actual situation. The results of a survey—implemented by the Ministry of the Environment, Japan—were analysed to examine the effectiveness and challenges of the survey methodologies. Mercury levels in ambient air, solid waste, emission flux, leachate water and human hair at waste disposal facilities in Cameroon, Indonesia, Kenya, Myanmar and Nigeria were analysed.
Ambient mercury levels at waste disposal facilities, where spontaneous waste combustion was observed, fluctuated significantly, although the average with the continuous monitoring was below 50 ng m−3. The factors for these fluctuations might be waste conditions, wind directions, distance from the waste combustion point, and others. The level was well below the guideline value for the workplace environment of the World Health Organization. Thus, it is unlikely for the site workers to develop adverse health effects caused by inhaling the ambient air.
The proportion of mercury emitted from waste disposal facilities, the quotient of daily mercury emission from the surface and daily mercury input to the facility were calculated. The results are 0.075%–1.32%, which indicated that less percentage of mercury input was emitted to the atmosphere and that the remaining will be accumulated in the facilities.
The methylmercury levels in hair were mostly below 1 μg g−1, which is below the equivalent to tolerable intake both for adults (4.4 μg g−1) and pregnant women (2.2 μg g−1). Thus, it is of no special concern for onsite workers regarding dietary mercury intake. Total mercury levels for most samples were also sufficiently low, but a few samples showed elevated mercury. The elevated levels might have been caused due to the application of personal care products containing mercury or accidental contact with other products containing mercury.
The survey has provided some useful insights into the mercury situation in waste landfill facilities in developing countries. The enhancement of mercury levels when and where open burning of waste is occurring needs further evaluation.
Mercury concentrations in ambient air at solid waste landfill facilities in developing countries with and without spontaneous waste combustion
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