The actual results of the Chernobyl accident were the subject of a conference. Some conclusions can be found here (boldface mine):

A total of 237 occupationally exposed individuals were suggested to be suffering from clinical syndromes attributable to radiation exposure and were admitted to hospital. Acute radiation syndrome (ARS) was diagnosed in 134 cases. Of these 134 patients, 28 died as a consequence of radiation injuries, all within the first three months. Two more persons had died at Unit 4 from injuries unrelated to radiation (and one additional death was thought to have been due to a coronary thrombosis). Gastrointestinal damage was a serious concern, causing early and lethal changes in intestinal function among 11 patients who had received doses greater than 10 Gy. The deaths of 26 of the 28 patients who died were associated with skin lesions that affected over 50% of the total body surface area. After the acute phase, 14 additional patients have died over the past ten years; however, their deaths do not correlate with the original severity of ARS and are therefore not necessarily and in some cases are certainly not directly attributable to radiation exposure.

...A highly significant increase in the incidence of thyroid cancer among those persons in the affected areas who were children in 1986 is the only clear evidence to date of a public health impact of radiation exposure as a result of the Chernobyl accident.

...The increase has been observed in children who were born before or within six months of the accident; the incidence of thyroid cancer in children born more than six months after the accident drops dramatically to the low levels expected in unexposed populations.

...It is now considered that the increase in the incidence of thyroid cancer in those exposed as young children may persist. This could increase the prevalence of thyroid cancer in the affected group in the future, requiring adequate resources for dealing with it.

...To date, only three children in the cohort of diagnosed cases have died of thyroid cancer. These post-Chernobyl papillary thyroid cancers in children, in spite of their aggressiveness, appear to respond favorably to standard therapeutic procedures if appropriately applied; however, only short term follow-up data are available as yet. There is thus a need for complete and continuing follow-up of the affected children in order to establish the optimal therapy. Life-long administration of L-thyroxine to children is mandatory after thyroidectomy.

Note that this effect is precisely the damage that the famous iodine pills are effective at preventing. A lot of people probably think they protect against all radiation.

Leukaemia, a rare disease, is a major concern after radiation exposure. Few fatalities due to radiation induced leukaemia would theoretically be expected according to predictive models (based on data from the survivors of the Japanese atomic bombing and others). The total expected excess fatalities due to leukaemia would be of the order of 470 among the 7.1 million residents of 'contaminated' territories and 'strict control zones', which would be impossible to distinguish from the spontaneous incidence of about 25,000 fatalities. The total expected figure among the 200,000 liquidators (who worked in 1986-1987) would be of the order of 200 fatalities against a spontaneous number of 800 deaths due to leukaemia. According to current models, about 150 of these 200 excess leukaemia deaths among the liquidators would have been expected to have occurred in the first ten years after exposure, for which the spontaneous incidence is 40. In summary, to date, no consistent attributable increase has been detected either in the rate of leukaemia or in the incidence of any malignancies other than thyroid carcinomas.

The rest of the summary is also worth reading.

In short, yes, most of the effect of a radiation attack would be psychological and economic, created by an overwhelming fear of radiation, far beyond its actual measurable effects. To be fair, some effects may show up later. The area needs to be watched.

Remember, the premise given in the BBC article was that actual damage from a dirty bomb would be minimal.

I submitted that the psychological and economic effects would be bad enough by themselves, due to the fear of radioactivity that far exceeds rational consideration of the actual effects.

You implied that Chernobyl showed the fear was justified.

The numbers show that, as major industrial accidents go, Chernobyl's actual casualty count is rather low. The psychological and economic damage is not low.

Add to this the fact that fear of nuclear power keeps us burning fossil fuels, dumping waste and CO2 into the air, and dealing with lunatic regimes who happen to be squatting on a lot of the oil supplies. I submit that this damage may far outweigh the measured ecological, economic, and human damage created even by several Chernobyl-style accidents.