natural toxin; naturally occurring poison
Refers to toxic substances produced by living organisms, such as plants, animals, fungi, or bacteria, as opposed to synthetic chemicals.
Food poisoning caused by natural toxins in mushrooms is reported every year.
The natural toxin in pufferfish is dangerous if not properly prepared.
人工毒 refers to synthetic or man-made poisons, the opposite of 自然毒.
Compound of 自然 (しぜん, 'nature') and 毒 (どく, 'poison').