One source of melamine exposure in the modern life is from the use of melamine tableware. This study examines whether the use of stainless steel containers can decrease melamine exposure in the daily life. The investigators hypothesize that, compared to those without use of stainless steel containers, university student volunteers with use of stainless steel containers excrete significantly lower melamine levels in urine.

Study subjects:

Two tiers:

1. Recruit 88 student volunteers from two university buildings and collect their morning one-spot urine specimens for 3 consecutive days (44 students in each building (Building A and Building B)
2. Select appropriate study subjects with high excretion of urinary melamine and with consuming melamine tableware containing hot water or hot soup by questionnaire in the past 3 days for intervention.

Study protocol:

This is a cluster randomized crossover intervention. We will conduct this study for 9 days and each experimental step lasts for 3 days. We randomly assign one building with 8 appropriate study subjects to a serial of control-intervention-intervention steps and another building with also 8 appropriate study subjects to a serial of control-control-intervention steps. Intervention step means study subjects will carry one big bag containing two stainless containers, one stainless spoon, and one stainless chopstick and use them for each meal during the trial (Some subjects will need to take pictures randomly and email back before the meal). Control means study subjects will carry one big bag without those stainless container, spoon, and chopstick and only use the containers provided by vendors for each meal during the trial (Some subjects will need to take pictures randomly and email back before the meal to check their adherence). Collect 24-hr urine samples for 9 days for melamine levels.

Inclusion criteria: 20-30 healthy students Exclusion criteria: Subjects with cancer, hypertension, diabetes, chronic hepatic or renal diseases, including urinary tract infection, or renal stones; Family history of renal stones; Body weight less than 50 kg.

Inclusion Criteria:

• 20-30-yrs healthy students

Exclusion Criteria:

• Subjects with cancer, hypertension, diabetes, chronic hepatic or renal diseases, renal stones;
• Family history of renal stones;
• Body weight less than 50 kg.