Attic cleaning probably isn’t your idea of a good time. But the dust, dander, and mold in that often-neglected room could be irritating your family’s lungs and kicking up allergies. 
Attic allergens and irritants constantly seep into your living area through ceiling hatches, doors, recessed lights, and heating and cooling systems (especially if they’re located in your attic).

Attic Cleaning Basics
Dust walls, window frames, and rafters with an electrostatically charged cloth (think Swiffer) or duster (cost: under $10), which grab twice as much dust as cotton cloths. Don’t forget to dust exposed roof trusses, attic fan blades, light bulbs, fixtures, hatches, and door frames.

Vacuum with a HEPA (high-efficiency particulate air) filter vacuum cleaner (cost: $200 to $400), which channels all vacuumed air through a filter designed to remove even microscopic particles. A less expensive choice: Install a top-quality, high-efficiency filter bag in your vacuum (cost: $8 to $10).
Line shop vacuums with a plastic bag, which traps irritants and makes debris disposal easy.
Wear a National Institute of Occupational Safety and Health mask (cost: $13), which filters a high percentage of airborne particles.
If you suffer from asthma and allergies — 60 million people in the U.S. do — hire a professional to remove the debris. Prices for pro attic cleaning vary depending on region and nature of the cleanup. Get an estimate before hiring a cleaning contractor.
This would be the basics for your attic. Next I can talk about mold and other irritants in the attic and how to deal with them.