Lifelines participants participating in general assessment 2A visited a location of their choice for a second time.
At the location, they underwent the following procedures:

• Collection of scalp hair
• Fasting venapuncture to collect blood samples for blood analyses and storage (8+ years old).
• Handing in of 24-h urine samples for urine analyses and urine samples storage (18+ years old)
• Handing in of timed overnight urine samples for urine analyses and urine samples storage (8-17 years old).

2A Visit 2 was preceded by 2A Visit 1 within, on average 40 days.
2A Visit 2 was accompanied by 2A Questionnaire 2 which was filled in, on average, 17 days (SD: ± 36 days) prior to 2A visit 2.
2A Visit 2 was the final part of general assessment 2A.

2A Visit 2 is procedurally equivalent to 1A Visit 2 and 3A Visit 2. The average time between 1A Visit 2 and 2A Visit 2 was 4 years.