Long-term practice of not blow-drying your hair after washing can lead to several potential risks and negative effects on the health and appearance of your hair. Here are some of the main hazards:

1. **Increased Risk of Fungal Infections**: When hair is left wet for an extended period of time, especially in a warm and damp environment, it creates a breeding ground for fungi and bacteria. This can lead to scalp infections such as dandruff or even more serious conditions like ringworm.

2. **Damage to Hair Cuticles**: Wet hair is more fragile and prone to damage. When left to air dry, the hair cuticles remain open for a longer time, making them susceptible to breakage, split ends, and overall weakening of the hair shaft.

3. **Frizz and Lack of Shine**: Air-dried hair tends to be frizzy and lackluster compared to blow-dried hair. This is because blow-drying helps to smooth the hair cuticles and seal in moisture, resulting in smoother and shinier hair.

4. **Scalp Irritation**: Damp hair left to air dry can cause irritation to the scalp, leading to itchiness, redness, and discomfort. This can be exacerbated if you have sensitive skin or existing scalp conditions.

5. **Mold Growth**: In extreme cases where hair remains consistently wet without proper drying, mold can start to grow on the scalp. This not only poses a health risk but also damages the hair follicles and can lead to hair loss.

6. **Unpleasant Odors**: Damp hair that is not properly dried can develop a musty or mildew-like smell over time. This can be embarrassing and difficult to get rid of without proper hair care practices.

In conclusion, it is important to ensure that your hair is thoroughly dried after washing to maintain its health and appearance. While air-drying occasionally is fine, relying on it as the primary method of drying your hair can have detrimental effects in the long run. Using a blow dryer on a low heat setting and applying heat protectant products can help mitigate some of the risks associated with blow-drying.