Yes, it is to a large extent.
This paper by Lian et al. explores the formation of volatile chlorinated compounds that are formed from reactions with organic nitrogen compounds, such as urea, amino acids, uric acid and creatinine.
The authors exposed both dilute solutions of uric acid and bodily fluid analogs (mixtures of compounds intended to mimic the composition of bodily fluids such as sweat and urine) to the sodium hypochlorite disinfectant used in swimming pools.
They showed by mass spectroscopy that uric acid, when exposed to sodium hypochlorite, forms the toxic compounds cyanogen chloride and trichloroamine, and the bodily fluid analogs also produce similar levels of these chemicals when exposed to sodium hypochlorite.
They also showed that physically adding uric acid (simulating urination) into actual samples of pool water caused the levels of cyanogen chloride and trichloroamine to increase:
The researchers conclude that:
Because uric acid introduction to pools is attributable to urination,
which is largely a voluntary process for most swimmers, opportunities
exist for significant improvement of air and water quality in pools
via changes in swimmer hygiene practices. Specifically, if swimmers
avoided urinating in pools, then air and water quality would likely
improve independent of other changes in water treatment or air