On the grass next to the Edwardian splendour of the Cartwright Hall art gallery they lay out their picnic rugs under a sunny West Yorkshire sky. But these are no ordinary families. For this is the annual Teddy Bears' Picnic for families taking part in one of the country's biggest research projects, studying the health of around 14,000 children born in the city. It is an attempt to get to the bottom of why illness blights the live s of so many families in Bradford, which is home to some of the most deprived communities in the UK.
Blood samples
Between 1996 and 2003, the number of children dying in Bradford before they reached their first birthday was almost double the average for England and Wales. Levels of childhood illness are higher as well, along with much higher rates of heart disease, diabetes, cancer, obesity, asthma and eczema in the city's population as a whole.
So the project, known as Born in Bradford, is looking at every aspect of a child's development to try to get an idea of how factors like environment, education, diet, ethnicity and genes interact together to affect our health.
Since March 2007, every pregnant woman who attended the Royal Bradford Infirmary has been asked to take part and - amazingly - nearly nine out of 10 said yes. Parents give blood and saliva samples, babies are measured and weighed and their progress will be tracked across the years.
Future health
Making his first appearance at this year's picnic is Jacob Robinson, born at the beginning of June to Nicola and Duncan. Jacob is the last recruit to the study and his parents are thrilled to be taking part. "I just think it is an incredible study," says Nicola.
"The fact they are speaking to so many mums across the whole area and compiling all of the data and using it for the future health of babies, I just thought it was a really important study so I was quite excited to be involved."
By lunchtime, more than a thousand people have gathered in the park where stalls promote everything from the Bradford Bulls rugby league side to how to practise good teeth-cleaning. At the centre of it all, chatting to parents and children, is Professor John Wright, the man in charge of the project.
"Bradford's got some major health problems. We have some of the highest infant mortality rates in the country, we have high levels of childhood asthma, childhood obesity, and we have a diabetes epidemic that is happening in this city as we talk.
"So what we wanted to do was to set up a study to understand what the causes of this were and in particular the early origins of these diseases, as they track through to adulthood.