I made my deposit this week in UK Biobank. I was recruited because my age lies between 40-69 and I live within 10 miles of an assessment centre. At least I do now: like a dodgy business, the centre (on the 3rd floor of a gloomy office next door to Zorba’s Snacks) will be here for six months and then move on to another town. I felt like I’d come to get a fake passport.

But inside the staff weren’t at all dodgy, and the process was painless. Process is the right word: in 90 minutes I was sized up, bled for my genes and other treasures, and dispatched with impressive and almost industrial efficiency. I ended up with a list of “good”” baseline results (why not ““normal”, though, a more neutral verdict?) and the feeling that I might end up in table 4 of a future BMJ paper.

It was fun trying to guess the rationale for some of the questions. Will “Q: do you sometimes speed on the motorway?” “A: sometimes” put me in a risk-taking category and predict my death at 90 from sky-diving? Perhaps it was just an honesty check.

And why did the computer ask for my parents’ first names and months of births but not their surnames? Not for record linkage, surely, as my surname’s different; and I’d already given their current ages and health status. Nor for sociodemography, as I’d answered the ethnicity questions. Maybe I would get their horoscopes at the end.

Questions about physical activity prompted mixed feelings – guilt at not doing enough, and amusement at the concept of “heavy DIY” (Ozzy Osbourne trying to put up shelves, maybe?). And did “how often do you use your mobile phone?” cover my frequency of making calls (A: virtually “never”) or sending emails (A: “all the time”)?

UK Biobank has been promised £61m ( 88; $111m) by the Wellcome Trust, the UK Medical Research Council, and the UK Department of Health. Launched in March 2007 after 8 years’ gestation, this is a grand cohort study with scope for numerous nested case control studies, some of them genomic. Early reactions to the plan were mixed, with concerns about the study’s commissioning, design, and limits – would UK Biobank find out too much or too little about the UK population?

The protocol, which is a remarkably good read, allows for a 10% response rate that yields 500 000 middle aged people. The tally on the day I attended was 186 632, according to the web totaliser, and there’s still another three years’ recruitment to do.  As the 1 in 10, I’ll be followed up through my routine contact with the NHS and, maybe, through further contacts and tests. Over the next 10 years UK Biobank will note whether I get cancer or a common chronic disease. After that – who knows what it’ll want from me?

Trish Groves is Deputy editor, BMJ