Environmental Assessment
Volume B-5.4
Mine
Human and Ecological Health
Ambatovy Project
368
January 2006
(i.e., change in downstream flow and water quality) (Volume A, Section 7.2,
Figure 7.2-1).
As the ore bodies generally lay on a high plateau and a drainage divide, the
headwaters of several basins originate within the ore body area. An
internationally recognized Ramsar wetlands system, the Torotorofotsy Wetlands,
is located immediately downstream of the mine site, and is included in the study
area.
5.4.3
Baseline Summary
5.4.3.1 Introduction
Evaluation of potential impacts on water quality for the mine project required
that baseline data be collected and assessed to describe background conditions
and to provide context for potential impacts associated with future operations and
closure.
A detailed description of the methods used for the screening-level risk
assessment and its results are found in Volume K, Appendix 4.1. A short
summary is provided below.
5.4.3.2 Methods and Main Results
Human Health
The human health assessment focused on ingestion of drinking water and fish.
The potential risks to critical receptors, i.e., a child (toddler life phase, from
seven months to four years of age) and a “composite” receptor (a hypothetical
receptor which experiences exposure for the first thirty years) were evaluated.
Arsenic, cadmium and nickel were considered chemicals of potential concern
under baseline conditions.
Levels of fish tissue met recommended values for fish consumption suggesting
that their ingestion as a regular food resource by people is unlikely to cause
health effects.
Non-carcinogenic risks associated with consumption of surface water as drinking
water are low and likely to be negligible. Conservative exposure models
(i.e., erring on the side of over-estimating exposure) suggest potentially elevated
health risks may exist for some human receptors regularly exposed to arsenic in
water in the mine area at baseline.
