Since I wasn't able to actually sell the Airpods (not as popular as they seemed here in Switzerland), I decided to open and test them with the EM meter I purchased some time ago when I set up our Unifi APs. There's one problem I've encountered: due to the W1 sensor's capability to detect when the AirPods are inside the ear, it's relatively hard to get them to play when they're not (which is necessary to measure the EM field) worn. I had to trick them a bit.
Now these numbers are hardly scientific - first of all, the EM meter I have isn't a professional one - its purpose was to identify WiFi dead spots in the house so I could properly place the APs - for that it doesn't need to be very accurate. Plus I lack the skills to test anything like this professionally, so this is merely anecdotal.
The bad news first: the EM field directed at the skull is indeed higher than with my Jabra sports headphones that I've been using for a while now. The good news, however, is that the part that actually goes into the ear (and thus bypasses the skull bone) is very well shielded. When measuring in direct contact with the actual bud, field levels were about the same as the Jabra's. The AirPods clock in at around 250-850 microV/m2 (depending on the angle of measurement - the part perpendicular to the head is around 850, the top part is lower) when measured at the buds and on the side facing the brain, while the Jabra also emits around 850. However, both AirPods emit the same EM field strength (which is a bit surprising, i thought only one of them is connected to the iPhone via bluetooth). With the Jabra, only the one with the transmitter in the right bud emits a significant EM field, while the left one is connected via wire and emits around 50 microV/m2. The Jabra is also very well shielded - on the outside-facing part of the bud, the EM field maxes out at around 1900.
The part where I guess the antenna sits in the Airpods (the small downward facing stick) emits beyond the 2000 mcroV/m2 my EM meter is capable of measuring - and it does so in all directions, including towards the neck / jaw.
So in review, it's more complicated to measure these things than I'd thought - but it's clear that in combination, they emit more than double as much EM radiation towards the head than the reference model I used. That's because both AirPods have a measured EM field of around 850 microV/m2 inside the ear and between 1900 and (over) 2000 microV/m2 on the outside part of the device at the back of the buds and the antenna respectively.
They do not transmit at 20 dBm (100 mW) as is the max for Bluetooth Class 1, however. According to the FCC filing, they max out at 12.5 dBM (17.8 mW), which is still almost double that of a normal Bluetooth Class 2 headset. Due to their excellent shielding, the exposure on the parts that are inserted into the skull is comparable to that of regular headsets, except that with regular bluetooth headsets, only one of the buds contains a transceiver, while with the AirPods both of them do.
And coming back to the FCC filing: the SAR value of 0.466 is reached when the measuring equipment touches the rear of the device (the one facing away from the skull). The front touch SAR is 0.028 (measured over 1g of tissue) or 0.010 (measured over 10g) - both of which are very low compared to what a regular mobile phone emits. And this confirms my observations that the device is excellently shielded towards the head.
Now what any of this means in terms of health beats me. Although I might come across as such, I'm actually not in the alarmists' camp - I've been using wireless devices for years for a variety of purposes, from headsets over phones all the way to home automation. I became interested in the topic because I have small children and I'd like to be able to make informed decisions when it comes to pretty much anything. If I can have the same functionality at lower RF exposure with certain products, I choose those, that's all.