Thank you for your suggestion. We have added the content we did not mention in this part, but the soil was not quartered, so there is no supplement. Now the modification is as follows: “Collect dust indoors or outdoors by cleaning dust from areas such as tables and windowsills. And 20 g of soil and as much dust (5-20 g) as possible were collected during the sampling process.” Point 5.
How much soil (kg) did you collect for each sample? Was the soil quartered? Page 3, lines 121-124: Please, add some information: How did you collect dust samples?