Final answer:
Pollution is the option among crime, poverty, war, and pollution that is generally considered an environmental issue as it directly pertains to the contamination and harm to ecosystems and natural resources.
Step-by-step explanation:
Among the options provided, the one that is generally considered an environmental issue is pollution. Environmental issues primarily relate to the damage or depletion of the Earth's ecosystems, resources, and climates. Crime, poverty, and war, although they can have environmental impacts and may be exacerbated by environmental problems, are not primarily categorized as environmental issues. Pollution directly affects the environment by leading to a loss of habitats, the destruction of ecosystems, and harm to both human and wildlife health.
Poverty, while not an environmental issue in its own right, can contribute to environmental degradation. For instance, the exploitation of natural resources, such as through excessive mining or deforestation, often occurs in impoverished areas leading to significant environmental damage. However, when considering the core of what constitutes an environmental issue, pollution is the fitting answer here as it refers explicitly to the contamination of air, water, or soil, which can stem from industrial activities, agricultural practices, waste disposal, and many other human activities.