WASHINGTON – Many poultry consumers are getting an unhealthy dose of sodium with their bird these days, the result of injections of saltwater during processing that many shoppers don’t realize have become common practice, according to consumer advocates and California chicken growers.

Two organizations, one for growers and one for consumer advocates, joined Wednesday with Sen. Barbara Boxer, D-Calif., in calling on the Agriculture Department to shed more light on the injections, known as plumping or enhancing, by preventing processors from labeling such chicken as ”100 percent all natural.”

Americans eat more than 20 billion pounds of poultry a year. In just the last few years, the percentage of chicken in grocery stores that has undergone the injections has risen from 16 percent to more than 30 percent, according to the California Poultry Federation.

Critics said the injections cheat consumers on two fronts: their health and their pocketbooks. They take in more sodium than what health experts recommend, and they pay for it because the injections add weight to the product — up to 15 percent more. They’re not asking for a ban of the practice, but for more forthright labeling guidelines.

Boxer said the extra weight amounts to about $2 billion in higher costs because consumers pay by the pound for most chicken products.